Manually update the compatibility of the VeeamBackup database (or custom named equivalent) via SQL Management Studio or using a query. The compatibility mode must be set to 2008 or newer.
Query:
Alter Database VeeamBackup set compatibility_level = 100
UI:
1. Connect to instance via SSMS
2. Right-click Veeam Database -> Properties
3. Select Options
4. Select Compatibility Level
5. Set to 2008, 2012, 2014 or 2016.