UFS Explorer Found Deleted Synology Photos, Then Refused the Saved Scan: Protect the RAID
Do not rebuild the Synology array, initialize either disk, or launch another long scan until you verify that UFS Explorer is opening the same reconstructed logical volume. A saved scan is associated with a particular storage object and layout. A different partition-offset warning is a reason to check the current disk and RAID mapping, not proof that the deleted photos are gone.
In this Synology SHR/Btrfs recovery case, two WD Red Pro disks had been expanded from 4 TB to 8 TB one at a time. An 11-hour UFS Explorer scan on an M3 MacBook Pro displayed roughly 2.5 TB of deleted Lightroom photos with filenames and working previews, and sample exports succeeded. Later the saved scan would not load. The OP had connected an external destination drive; unchanged files in the 7.27 TB logical volume could be browsed, but some gave an 'Unable to read source file' error. The cause of the offset mismatch was not established.
Can the Saved Scan Be Reopened Without Rescanning?
First preserve the scan database and its original diagnostic information. Then compare the connected physical disk identities, sizes, order and reconstructed SHR/Btrfs volume against the setup selected for the successful scan. Verify the source object in UFS Explorer rather than assuming that the same USB dock and port guarantee the same enumeration.
UFS Explorer documents loading a saved result onto the previously scanned storage and distinguishes a completed scan-result database from a paused scan-status file. Try the documented load procedure only with the matching source volume. Do not force an offset match or change the array metadata just to satisfy the warning.
When Do Read Errors Change the Plan?
The failing exports of currently existing files are a separate warning. They could involve dock access, drive read errors or assembly problems; a screenshot or a saved-scan error cannot identify which. If stable access cannot be demonstrated, stop experiments and obtain professional RAID imaging help. An 8 TB per-disk source also requires substantial healthy destination capacity to preserve independently.
If the NAS previously had enabled Btrfs snapshots, check available snapshots or backups without modifying the only source copies. Synology supports browsing and copying files from snapshots where such snapshots exist. If there are no snapshots, maintain the read-only array configuration and export the verified photos to an independent drive; do not recover them onto either NAS member.
Recoverit NAS Data Recovery may be relevant to a separately accessible NAS volume, but it is not a substitute for fixing this UFS Explorer saved-result association or proof that it can reconstruct this particular disconnected SHR arrangement.