If you are using Veeam 8 SQL explorer you might discover that you cant see any databases. This is normally down to the SQL permissions that the account the job runs under. The permissions the account needs are :-
Instance level:
DBcreator
public
DB level:
db_backupoperator
public
For aux databases:
db_backupoperator
db_denydatareader
public
Securables:
view any definition
view server state
Once the permissions have been changed you will need to run an Active full backup