Challenge
Veeam Backup Enterprise Manager fails to collect data from a Veeam Backup server with the following error:
Return argument has an invalid type.
The following error can be seen in VeeamBES.log:
[timestamp] Info Reporting data were successfully collected from the server [server.local]
[timestamp] Error Interrupting collect session. Return argument has an invalid type.
[timestamp] Error Unable to collect data from Veeam Backup Server xxx.xxx.xx.x
[timestamp] Error System.InvalidCastException: Return argument has an invalid type.
Cause
The version of Veeam Backup Enterprise Manager differs from the version of Veeam Backup & Replication.
Solution
Make sure that Veeam Backup Enterprise Manager and Veeam Backup server have the same version. Veeam Backup Enterprise Manager can only collect data from backup servers of the same version.