In my case I had renamed the computer from a default WIN234dfasd type name to a ‘much’ better alternative. Veeam refers to the local computer name in a couple of registry entries and promptly stopped working – which we didn’t notice until later.
The keys are:
CODE: SELECT ALL
HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\SqlServerName
HKLM\SOFTWARE\Veeam\Veeam Backup Catalog\CatalogSharedFolderPath