after a disk crash on my Synology NAS, I moved my backup files to a web hoster.
It took me a short while to get it up and running. After changing wp-config.php it still wouldn’t run. Cause: There seems to be a small difference in the Synology installation. What did I do? I just overwrote my WordPress copy with a new version. That fixed it.
Sorry to hear but glad that you had a backup and found this solution. I will continue to play around with Synology even though the WP install has its strange bugs too (repeatedly after a DSM update WP pages would not load anymore)