1664 - Archiving fails with "account mismatch" errors

Symptom

Archiving fails with errors such as the following:

Could not process 'C:\Directory\Folder\file.pdf' (account mismatch)
Rehydrating 'C:\Directory\Folder\file.pdf' (account mismatch)

Cause

When InstantData Permanent is used to restore from a cloud backup, we do not use the encryption key but instead create a secure restore session for the account. This session serves as the credentials needed by the InstantData service to perform the restore. The session lasts for 24 hours.

InstantData Permanent works by creating stub files for all the data that is to be restored, and rehydrating the stubs either sequentially or on demand as they are accessed, whichever occurs first for a particular stub file. Sequential rehydration only continues as long as InstantData Permanent remains open. If InstantData Permanent is closed, rehydration is interrupted, leaving behind stub files on the machine that reference the cloud account being restored. These remaining stub files will be rehydrated on demand by the InstantData service, but once the restore session expires after 24 hours of inactivity, the account credentials needed for the InstantData service to rehydrate these stubs are no longer accessible. 

If you now try to open one of the files that have not been rehydrated, you will see an error. The archiving task in ESE will attempt to rehydrate stubs that don't match the archiving criteria (including stubs from a different backup account), but in this case rehydration will fail because the InstantData service no longer has the necessary credentials for the cloud account. ESE backups will similarly fail with errors because the backup cannot access the stubbed cloud file contents.

Solution

To remove the account mismatch errors:

1. From RedApp, download InstantData Permanent for the affected cloud account again and run the application on the same machine as before. You do not need to restore any files; getting to the point of browsing the backup will be sufficient to update the InstantData service with a new session for this account.

2. Immediately afterwards, open ESE on this machine and manually run an archiving task. After scanning the disks for eligible files, ESE will attempt to rehydrate any stub files associated with a different backup account. Because a valid restore session is in progress, rehydration should be successful. Depending on the size and number of stub files, this could take some time.

Once archiving completes, there should be no further stub files for the cloud account present, and the error should stop showing up in the logs.

To prevent account mismatch errors in future:

Always allow the InstantData Permanent application to complete a restore before closing it.