Error code: 0x80020009. The ALTER TABLE statement conflicted with the FOREIGN KEY constraint "FK_SanVolumeRescanPolicy.host_id". The conflict occurred in database "VeeamBackup", table "dbo.Hosts", column 'id'.
Looks like the issue happens during configuration database upgrade. An attempt to create a foreign key constraint between 2 tables is failed due to discrepancy of values in these tables.
This is not something we can help to fix over forum posts. Please don't hesitate to request escalation of your case.
Hi Andrey, this comes down to the known issue where the database records were not properly cleaned up after removing the storage from infrastructure in Veeam B&R. I can see that our support engineers were able to assist you with DB cleanup already. (BTW, the correct support case number is 04013259.)
For future readers: The issue was addressed in v10 so the database will be cleaned up correctly starting from this version. However, if the storage removal occurred in the previous version, you still might encounter a similar issue during the upgrade. Please contact support directly for assistance.