Server is unable to open backup server database

My UrBackup server has stopped working. On checking the log files, I found the following:

After the default partition filled up faster than expected, I moved the database files to a different partition and created a symlink to them (using the command from this post ). This worked for a time, but I wanted to move them to an SSD. The files were inaccessible after I moved them to the SSD, so I had to use testdisk to copy them back to the original location.
I tested the symlink (i.e. cat /var/urbackup/server_token.key gave the correct key).
I am not sure why the server is unable to open the database file. I would greatly appreciate any help with diagnosing this or a suggestion if someone has encountered a similar error.

Issue was with file permissions within the database. Updating those permissions to allow more access solved the issue.