After upgrading Enterprise Manager and Backup server to version 9, RestAPI requests to tenant entities fail with "Specified cast is not valid" error.
During the first data collection, Enterprise Manager v9 replaces "0" with "NULL" in some tenant-related database fields.
1. Log in to veeam.com and download this script
2. Stop Veeam Backup Enterprise Manager service
3. Open MS SQL Management studio and connect to the instance hosting Enterprise Manager database.
4. Right-click on Enterprise Manager DB (default name VeeamBackupReporting) -> New Query
5. Copy/paste the contents of the text file into SQL query window
6. Execute the query
7. Start Veeam Backup Enterprise Manager service