ERROR_FILE_EXISTS [CopyFileEx] on Samba share

[mikexx]

How do I get rid of theses 29,000 errors?

1) I make sure there are no ".ffd_tmp" files omn the NAS drive and delete any that I see.

2) I run FFS Version 11.3 - 64 Bit - 02/11/2020 and I get the following errors.

3) I'm also left with 30,000 useless "*.ffs_tmp" files on the NAS drive, which I can of course delete once again.

I added the Exclude filter, *~* since this seems to be rated with filepaths that include tilda "~". But these filepaths aren't filtered out when doing the synchronise.

This is more than a little annoying!

"C:\Program Files\Internet Explorer\ExtExport.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ExtExport~2693.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\hmmapi.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\hmmapi~4e04.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\iediagcmd.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\iediagcmd~a540.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\ieinstal.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ieinstal~67ae.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\ielowutil.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ielowutil~8737.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\IEShims.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\IEShims~9dae.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\iexplore.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\iexplore~0a15.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\sqmapi.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\sqmapi~2822.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\NVIDIA Corporation\license.txt" to
"\\DNS-323-1\Backup\C-Backup\Program Files\NVIDIA Corporation\license~f5a7.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\SoftEther VPN Client\vpn_client.config" to
"\\DNS-323-1\Backup\C-Backup\Program Files\SoftEther VPN Client\vpn_client~467d.ffs_tmp".
ERROR_ACCESS_DENIED: Access is denied. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\AMMonitoringProvider.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\AMMonitoringProvider~751c.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\ConfigSecurityPolicy.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\ConfigSecurityPolicy~4b17.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\DefenderCSP.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\DefenderCSP~525b.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\EppManifest.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\EppManifest~39e7.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpAsDesc.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpAsDesc~455a.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpAzSubmit.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpAzSubmit~c34e.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpClient.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpClient~7a7b.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpCmdRun.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpCmdRun~9340.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpCommu.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpCommu~588f.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpEvMsg.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpEvMsg~dbd8.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:25:33     Error:     Cannot copy file
"C:\Program Files\Windows Defender\MpOAV.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Windows Defender\MpOAV~ca6b.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
[…]Showing 25 of 28,962 items


[Zenju]

Maybe there is something interesting in the logs: https://freefilesync.org/faq.php#trace

[mikexx]

If I look at the offending line from the Process Monitor screen output I get:

High Resolution Date & Time: 23/11/2020 20:42:08.2455887
Event Class: File System
Operation: CreateFile
Result: EAS NOT SUPPORTED
Path: \\DNS-323-1\Backup\Program Files\Internet Explorer\ExtExport~ba93.ffs_tmp
TID: 8708
Duration: 0.0086388
Desired Access: Generic Read/Write, Delete, Write DAC
Disposition: Create
Options: Sequential Access, Non-Directory File
Attributes: A
ShareMode: None
AllocationSize: 54,784

If this isn't sufficient I can email you the PML file where I have cropped the output before the file creation attempt and the final closing of the source file.

HTH

The burning question, why the EAS error. I associate this with "Exchange ActiveSync Mail Server", but why is FFS using this?

[Zenju]

If this isn't sufficient I can email you the PML file

Yes, it would be great to have another sample of this issue for reference. I already have a similar PML file for Windows 7 which has lead to the following analysis:

This is a Samba network driver bug that hasn't been fixed for years (who's responsible for your network driver? Microsoft?).

The problem is when CopyFileEx detects that the source file has NTFS extended attributes (EA), like in your case, it first tries to open a file handle on the target network location with "Read Data" access right:

Desired Access:    Generic Write, Read Data/List Directory, Read Attributes, Delete


=> this operation fails with EAS NOT SUPPORTED

So far so good. Network doesn't support EA, okay.

Problem: Despite the error, a 0-sized file has been created on the network that was not cleaned up!

Next CopyFileEx tries to skip EA and copy the file normally, so it opens the target handle without EA support:

Desired Access:    Generic Write, Read Attributes, Delete


=> this operation also fails: NAME COLLISION

This is the NT equivalent of Win32 ERROR_FILE_EXISTS! It can't create the file, because a 0-sized garbage file was left over from the previous operation!

Only now CopyFileEx fails with ERROR_FILE_EXISTS and gives control back to FreeFileSync, which is in a bad situation to detect this mess. There is no way to know that this (garbage) file on the network target folder wasn't there before the copy attempt, so it has to leave it there.

[mikexx]

Many thanks for the explanation. I have emailed you a cropped PML file but uncertain it will give you much additional information.

While I agree that the server leaves a a mess for FFS, it should be apparent to FFS that:

1) There wasn't a xxxx.ffs_tmp file before the error
2) there is a zero length xxxx.ffs_tmp after the error.

Could you not set a flag and look for the file ending, which must be unique to FFS, and zero length, in order to delete a zero length file?

The NAS drive is a D-Link unit running ALT-F which is currently using SMB v1.0

I can run SMB v2.0 but then the file structure beomes invisible to File Explorer, though I can still access the drive by manually by typing in the name/IP address.

[Zenju]

Thanks! On Windows 10, the file operations inside CopyFileEx are slightly different:

Desired Access:    Generic Read/Write, Delete, Write DAC
=> EAS NOT SUPPORTED

Desired Access:    Generic Write, Read Data/List Directory, Read Attributes, Delete, Write DAC
=> NAME COLLISION

Desired Access:    Generic Write, Read Attributes, Delete, Write DAC
=> NAME COLLISION


The NAS drive is a D-Link unit running ALT-F which is currently using SMB v1.0

I can run SMB v2.0 but then the file structure beomes invisible to File Explorer, though I can still access the drive by manually by typing in the name/IP address.

Would be interesting to know if this is a SMB v1.0 bug that is fixed in SMB 2.0 or if the bug is originating somewhere else.

While I agree that the server leaves a a mess for FFS, it should be apparent to FFS that:

1) There wasn't a xxxx.ffs_tmp file before the error
2) there is a zero length xxxx.ffs_tmp after the error.

Could you not set a flag and look for the file ending, which must be unique to FFS, and zero length, in order to delete a zero length file?

Essentially the question becomes how much hackery is justified to work around this bug in third-party code. OTOH Windows Explorer doesn't suffer from this bug because it isn't using Microsofts very own CopyFileEx. Maybe FFS should get rid of CopyFileEx entirely (which doesn't offer a lot of functionality anyway that couldn't be achieved differently).

[mikexx]

Right, I'm not sure which version of Samba I'm running but believe it may be 3.6.25. I have the option of SMB1 and SMB2. Both were ticked initially.

Choosing SMB1 and SMB2 over the other or both made no difference. However on the share there is a tick-box for "Inherit Perms" which when ticked made the problem go away.

I have no idea what permissions are those being inherited but I no longer get these hanging zero length files.

I hope this has been of use to you and others.

[Chribaa]

Hi Mikexx, hi Zenju,

I read your exchange with much interest, as I have the same problem. When FFS tries to copy files from my C-Drive to my NAS (in my case a Synology DiskStation 710+ running DSM 5.2 in the most current version), I get these errors and no files get updated. FFS becomes almost useless this way. I tracked it with Process Monitor - and the above is exactly true in my case as well (EAS NOT SUPPORTED -> NAME COLLISION and left over 0-size .ffs_tmp files)

Interesting is, that FFS can copy files from a USB-Stick (mapped as D-drive) to the DiskStation w/o any problems regardless of whether it is formatted with FAT or with NTFS.
So, I guess the reason for the errors needs to lie in the file-system of my C-drive (The Laptop is a Lenovo Thinkpad X1 Yoga running Win 10 Enterprise in Version 10.0.19042.)
Can you help me with a hint, how I can rectify this?

@Mikexx: when you said you ticked a box for "inherit perms" on the share, I assume, this was a flag in the OS of you NAS-drive, correct? On DSM there is no such flag, as there the default is, that permissions are inherited anyway...

Thanks so much for your help!

[Marek-M]

I have the same problem with my NAS drive. The error "ERROR_FILE_EXISTS: The file exists. [CopyFileEx]" makes it very difficult to sync data. From what I read, there is little chance that FreeFileSync will handle it. Is it possible for FreeFileSync to create a BATCH file in such a situation, which would contain a list of files that ended with such an error during FreeFileSync synchronization? With such a file it would be possible to manually copy files that FFS skipped due to an error. Below is an example of a few bugs from the first post along with the proposed BATCH file content for them:

*** LIST OF ERRORS [CopyFileEx] FROM FIRST POST ***
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\hmmapi.dll" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\hmmapi~4e04.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\iediagcmd.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\iediagcmd~a540.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\ieinstal.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ieinstal~67ae.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]
05:24:55     Error:     Cannot copy file
"C:\Program Files\Internet Explorer\ielowutil.exe" to
"\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ielowutil~8737.ffs_tmp".
ERROR_FILE_EXISTS: The file exists. [CopyFileEx]

*** GENERATED BATCH FILE CONTENT: ***
XCOPY /y  "C:\Program Files\Internet Explorer\hmmapi.dll" "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\hmmapi.dll"
DEL /f /q "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\hmmapi~4e04.ffs_tmp"
XCOPY /y  "C:\Program Files\Internet Explorer\iediagcmd.exe" "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\iediagcmd.exe"
DEL /f /q "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\iediagcmd~a540.ffs_tmp"
XCOPY /y  "C:\Program Files\Internet Explorer\ieinstal.exe" "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ieinstal.exe"
DEL /f /q "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ieinstal~67ae.ffs_tmp"
XCOPY /y  "C:\Program Files\Internet Explorer\ielowutil.exe" "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ielowutil.exe"
DEL /f /q "\\DNS-323-1\Backup\C-Backup\Program Files\Internet Explorer\ielowutil~8737.ffs_tmp"


[jbit]

I have exactly the same problem using my D-Link NAS DNS-320L with ALT-F firmware, SAMBA 3.6.25 with SMB 1 and SMB2 enabled. FFS cannot write SOME *-ffs_tmp files in target drive, while other files were written correctly.
I experienced this problem using a Lenovo Thinkpad /480 (Windows 10 Enterprise, build 10.0.19043) managed by enterprise (that includes many restrictive policies to access USBs and maybe other files.

In order to validate the problem, I copied all my files (the files that I was not able to sync before) from Lenovo T480 to my owned destop (Win 10). Then I synced my desktop with my D-Link NAS without ANY problem. FFS does NOT create random *.ffs_tmp files and it syncs perfectly.

Then, I firmly believe that this problem is related either something weird in Lenovo or related to some enterprise company policy that prevents CopyFileEx to work 'freely' as it does in a non-managed computer.

Does it make sense?

[Zenju]

Essentially this bug needs to be fixed by Microsoft (either their CopyFileEx or Samba implementation is broken).

It doesn't look like this is going to happen since Microsoft isn't suffering from this bug: Windows Explorer reinvented the (file copy) wheel, and isn't using the system function CopyFileEx.

Let's hack around this: If the failure code is ERROR_FILE_EXISTS and the target file size is 0, FFS will assume the Samba bug described here, clean up the orphan file, and restart file copying using streams instead.

Can you test the following version and see if it fixes the issue? https://www.mediafire.com/file/9ixo27xobw7le66/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25282%2529.exe

[Marek-M]

Hi Zenju!
Unfortunately "FreeFileSync 11.15 Beta" does not solve the problem. I temporarily deal with copying bugs from FreeFileSync. I paste the messages into Excel, where I transform them into commands for the BATCH script. So far, this is a working alternative.

[Zenju]

Hi Zenju!
Unfortunately "FreeFileSync 11.15 Beta" does not solve the problem.

What do you mean? What (new) error messages are you seeing now?

[Marek-M]

I still have errors of this type (for 17 different files):

18:49:20    Błąd:    Nie można skopiować pliku
"P:\#FOLDER\FILE.xlsm" do
"\\nas326\#FOLDER\FILE~abc1.ffs_tmp".
ERROR_FILE_EXISTS: Plik istnieje. [CopyFileEx]


[Zenju]

The only chance for this error message showing, is that there is some issue with correctly detecting this bug in the beta version. (CopyFileEx shouldn't have been used!) Can you send a Process Monitor trace (https://freefilesync.org/faq.php#trace) for a sync where at least one of these ERROR_FILE_EXISTS occurs that leaves behind an empty ffs_tmp file?

[Zenju]

I still have errors of this type (for 17 different files):

18:49:20    Błąd:    Nie można skopiować pliku
"P:\#FOLDER\FILE.xlsm" do
"\\nas326\#FOLDER\FILE~abc1.ffs_tmp".
ERROR_FILE_EXISTS: Plik istnieje. [CopyFileEx]


Thanks for the PML file! There are 16 "EAS NOT SUPPORTED" logged.

Question 1 is: Do all of these failures leave a zero-byte garbage file behind, or only some of them?

In the pml file, after CopyFileEx failed with "EAS NOT SUPPORTED", the FFS test version tries to check the file size on the target, but this fails with ERROR_FILE_NOT_FOUND, so the workaround to use an alternate copy routine is not triggered.

Question 2 is: if zero-byte files are indeed left behind each time, why is FFS getting ERROR_FILE_NOT_FOUND? Maybe it's a buffering issue? The following version tries to disable buffering and get an accurate estimate whether the 0-byte target files exists or not:
https://www.mediafire.com/file/iuw2xfehga276tl/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25286%2529.exe

[watrworld]

So any fixes to this issue? FFS is unuseable at this point.

[Marek-M]

Question 2 is: if zero-byte files are indeed left behind each time, why is FFS getting ERROR_FILE_NOT_FOUND? Maybe it's a buffering issue? The following version tries to disable buffering and get an accurate estimate whether the 0-byte target files exists or not:
https://www.mediafire.com/file/iuw2xfehga276tl/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25286%2529.exe

FreeFileSync 11.15 2021-10-11 synchronized the files without these errors. Another synchronization in a week - I hope it will also be smooth. Thank you for your help.

[NickDickinsonWilde]

Using 11.15 beta (2021-10-11) and getting the `ERROR_FILE_EXISTS: The file exists. [CopyFileEx]` message.
Despite no file existing that I can see.
PML sent via email.
Using external harddrive connected to a Telus (Canadian ISP) provided router - model #T3200M.

[pkiff]

Just quickly popping in to say that this has been an issue for me over the past several months as well. I sync several different computers to files on a Buffalo NAS network drive running Linux and Samba. Like jbit above, I'm experiencing problems on a Lenovo Thinkpad (P52) running Windows 10, but managed by a centralized admin.

I have wondered if the issue is related to a corporate OneDrive and/or crappy corporate Anti-Virus configuration. The files it affects seem to be random. And it only occurs when I initiate the Sync from my corporate machine. If I initiate the sync from my personal machine (also a Thinkpad running Win 10), then I don't get any issues. But once I get a file exists error, the only way for me to fix it when syncing either machine is for me to go find the culprit file locations and delete the 0-byte files that are stopping it from working.

I'm still on 11.14. My corporate install (where I get the bugs) is a free version, my personal install (where I don't get bugs) is a donation version.

[watrworld]

I'm waiting for a Portable version of 11.15 to try. On my work machine, I do not have admin rights. I did try to install on another laptop and selected the portable version, and moved it over to my corp machine, but it complained that it wasnt installed on the same os. So much for portable!!

[xCSxXenon]

https://freefilesync.org/faq.php#portable
Not to derail the thread, but read this for the portable information. You can't just copy them over to a different computer without issue. You have to run it from a USB drive.

[Marek-M]

Question 2 is: if zero-byte files are indeed left behind each time, why is FFS getting ERROR_FILE_NOT_FOUND? Maybe it's a buffering issue? The following version tries to disable buffering and get an accurate estimate whether the 0-byte target files exists or not:
https://www.mediafire.com/file/iuw2xfehga276tl/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25286%2529.exe

FreeFileSync 11.15 2021-10-11 synchronized the files without these errors. Another synchronization in a week - I hope it will also be smooth. Thank you for your help.

Next week with backup and no NAS synchronize problems. For me issue is fixed in FreeFileSync Beta 11.15 2021-10-11

[watrworld]

https://freefilesync.org/faq.php#portable
Not to derail the thread, but read this for the portable information. You can't just copy them over to a different computer without issue. You have to run it from a USB drive.

Except, that I cannot even start the silent install as it requires admin rights, so I do have to do it from another computer.

[xCSxXenon]

You don't use the silent install for the portable version. You haven't downloaded the portable version by the sound of it. Go to your donation page and click the portable download link, not the Windows installer.

[Zenju]

Using 11.15 beta (2021-10-11) and getting the `ERROR_FILE_EXISTS: The file exists. [CopyFileEx]` message.
Despite no file existing that I can see.
PML sent via email.
Using external harddrive connected to a Telus (Canadian ISP) provided router - model #T3200M.

This seems to be an unrelated issue. E.g. there's \\192.168.1.254\admin\Images\2017\20170313_161923.jpg, and CopyFileEx fails with ERROR_FILE_EXISTS. FFS tries to get its size, and this in fact succeeds with "3.106.383" bytes. Whatever the reason this file exists (maybe you're running multiple syncs in parallel), the ERROR_FILE_EXISTS error seems legit.

[Zenju]

Next week with backup and no NAS synchronize problems. For me issue is fixed in FreeFileSync Beta 11.15 2021-10-11

Sounds promising! I can't release the code in the beta in the current form. First need to find out, which setting did the trick:

Are you able to reproduce ERROR_FILE_EXISTS that is leaving behind a zero-byte file with FFS 11.14 for a specific file?

If yes, let's do a few more tests:

1. Are able to copy with this version? https://www.mediafire.com/file/g0dh2z06edwysxd/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25287%2529.exe
2. And with this? https://www.mediafire.com/file/6au4qqxd5ej85e9/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25288%2529.exe
3. This one? https://www.mediafire.com/file/je3629022tumg9d/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25289%2529.exe

[watrworld]

You don't use the silent install for the portable version. You haven't downloaded the portable version by the sound of it. Go to your donation page and click the portable download link, not the Windows installer.

Except 11.15 is not yet available as its in Beta, only 11.14 show on my donation page.

[Marek-M]

Next week with backup and no NAS synchronize problems. For me issue is fixed in FreeFileSync Beta 11.15 2021-10-11

Sounds promising! I can't release the code in the beta in the current form. First need to find out, which setting did the trick:

Are you able to reproduce ERROR_FILE_EXISTS that is leaving behind a zero-byte file with FFS 11.14 for a specific file?

If yes, let's do a few more tests:

1. Are able to copy with this version? https://www.mediafire.com/file/g0dh2z06edwysxd/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25287%2529.exe
2. And with this? https://www.mediafire.com/file/6au4qqxd5ej85e9/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25288%2529.exe
3. This one? https://www.mediafire.com/file/je3629022tumg9d/FreeFileSync_11.15_%255BBeta%255D_Windows_Setup%25289%2529.exe

I will try to do these tests next Sunday - this is my backup day :) Thank you for your patience.

[NickDickinsonWilde]

Using 11.15 beta (2021-10-11) and getting the `ERROR_FILE_EXISTS: The file exists. [CopyFileEx]` message.
Despite no file existing that I can see.
PML sent via email.
Using external harddrive connected to a Telus (Canadian ISP) provided router - model #T3200M.

This seems to be an unrelated issue. E.g. there's \\192.168.1.254\admin\Images\2017\20170313_161923.jpg, and CopyFileEx fails with ERROR_FILE_EXISTS. FFS tries to get its size, and this in fact succeeds with "3.106.383" bytes. Whatever the reason this file exists (maybe you're running multiple syncs in parallel), the ERROR_FILE_EXISTS error seems legit.

Interesting. I guess I'll look more into it. Definitely not running multiple syncs. One sync and if I'm in (windows) explorer in the folder, I see it flicker as a file is created and then disappears. Thanks.