1. Remove the Veeam 9.5 from the server and all proxies.
2. Established Veeam 9.0 on the server, install the update.
3. Import configuration from backup.
4. After setting the components installed on all proxies.
5. I check that all works are backups.
Virtual Center 6.5, part of the hosts to 6.5, part 6.0. Several machines linux on 6.5 hosts (also compatible 6.5 or higher) has been successfully backed up.
I am waiting for update 1 to 9.5 for a new attempt.
P.S. Day disappeared...
P.P.S. Support case number is 01984429.