Using [drive name] compare fails

[NPC]

I set up a mirror of most of a second internal HD (D:\) to a removable USB HD which is identified by its name rather than drive letter. I ran the backup successfully and saved it. But when I reopen the backup and attempt a 'Compare' it fails with a 'The following folders do not yet exist' error.

The relevant folders do exist. Here is a screenshot showing the result of the 'Compare', with Explorer windows showing the folders. The target at the top of the FFS window shows 'G:\D Drive\To Send'

Result of Compare.png (265.42 KiB) Viewed 1108 times

If I close FFS and eject the drive, then reopen FFS the target shows as "?:\[LightrmBkup]\D Drive\To Send" which seems to show that FFS understands the relationship between G:\ and [LightrmBkup]. If I then plug in the drive, the target stays "?:\[LightrmBkup]\D Drive\To Send".

What am I doing wrong?

[xCSxXenon]

You spelled "Lightroom" wrong in the 3rd row, on the right side

[NPC]

Thanks xCSxXenon - so I did!

But that isn't what was causing the issue. Eventually I found a nugget in the manual:

"Daylight Saving Time (Windows)
A common problem synchronization software has to handle is +-1 hour file time shifts after a Daylight Saving Time (DST) switch has occurred. This can be observed, for example, when a FAT32- or exFAT-formatted volume (in the following called "FAT") is compared against an NTFS volume, like when synchronizing a USB memory stick against a local disk. Files that previously appeared to be in sync are now shown with a one hour modification time offset, although they have not been modified by the user or the operating system.

The reason for this behavior lies in the way NTFS and FAT store file times: NTFS stores time in UTC format, while FAT uses local time."

So rather than fiddling about with the Comparison settings I bit the bullet, re-formatted the drive to NTFS and re-synced the drives. Since there is over 2.6 terabytes of data, this predictably took a day to complete. But it was worth it; all is now well and the mirror compares as expected.

I would suggest that this potential issue is highlighted in the quick start 'Basic Usage' section at the beginning of the manual, since this is inevitably what users will try when starting out. Just a brief warning with a link to the Daylight Saving Time article further into the manual https://freefilesync.org/manual.php?topic=daylight-saving-time would save a lot of heartache, since the majority of Windows internal drives are formatted NTFS while the majority of USB External drives and USB sticks are formatted exFAT or FAT32.

[xCSxXenon]

Gotcha, glad you got it working. To be clear, the DST issue had nothing to do with your initial description and picture, which was regarding a warning: 'The following folders do not yet exist'.
I wonder if it might be a good idea to detect FAT filesystems and automatically set a 1-hour offset, or detect these scenarios and pop up a message that describes the analysis and offers to set the offset from that message directly. @Zenju