Ubuntu - FFS no longer writes to password-protected drive

[syncORswim]

I'm a donating user and I've been using FreeFileSync for many years, first on Windows and now on both Windows and Ubuntu Linux. I love the program, but it just quick working for my particular situation. I wanted to report this and see if there is a solution or if I've found a bug.

My setup:
I'm running Ubuntu 22.04 and I back up to a password-protected external drive. Drive passwords are stored in ~/.smbcredentials and very recently FreeFileSync can no longer read that file (or perhaps it never needed to before?). In any case, I get the following error upon Synchronization:

Cannot open file "/home/myusername/.smbcredentials".
EACCES: Permission denied [open]

If the error is ignored and FFS pushes ahead, the drive becomes read-only (until restart) and the sync fails. If I click "Cancel" when the error appears, the drive remains writeable, but of course no Syncronization has occurred. I'm stuck here without a backup.

Thinking this might be a permissions issue regarding manual installation via the .run file, I tried installing the Ubuntu Software Center version (Flathub / Flatpak) but the results were the same.

Additional observations:
• FreeFileSync writes sync_ffs.db files to the drive just fine during the Compare process
• Canceling the Synchronization process at the "~/.smbcredentials" error will successfully write a log entry to the external drive.

Something is happening specifically during the Synchronization process that kills the drive's ability to be written to, and it appears to be related to FFS asking for .smbcredentials access when it seems to not need this in the first place.

[syncORswim]

Other (failed) workarounds tried:
• Installing FFS for single user (vs all users)
• Running FFS as root - While there's no error message about not being able to read .smbcredentials, the password-protected drive becomes instantly read-only upon Syncronization and the process fails.

[syncORswim]

Update: It appears it could simply be a failing drive. I'll report back if not, but that seems a plausible explanation.

[syncORswim]

I've confirmed that it is indeed FreeFileSync that cannot write to three confirmed working drives due to the .smbcredentials access problem. They are all BitLocker encrypted, if that makes any difference, but it's natively supported by Ubuntu. Anyone had an issue like this or think they know what might be the cause? I'd hate to have to stop using FFS over this.

[xCSxXenon]

This sounds more like an issue in the FUSE process. Are you sure that the password(s) in the credentials file are correct? Are you sure that the file is actually intact and readable? Is the local OS disk failing or does it possibly have a dirty file system?