Veeam Backup and Replication does not start after Enterprise Manager update 9.5 U4

Challenge

Both Veeam Backup and Replication and Enterprise Manager are installed on the same server. Enterprise Manager is updated to Update 4 with instance license, while Veeam backup and Replication is still running an older version. After Enterprise manager update it will not start with the following error message:

Cause

Veeam Backup and Replication 9.5 Update 3a or earlier do not support instance-based licenses

Solution

1. Close Veeam Backup and Replication shell

2. Remove license information from registry:

3. Start Veeam Backup and Replication shell (it will be running in a Free mode)

4. Remove ESXi hosts version 4.1 which are no longer supported.

5. Close Veeam Backup and Replication shell and upgrade with instance license