Unable to start Plesk migration: urlopen error [Errno 99] Cannot assign requested address

Symptoms

When trying to start a migration the following error appears:

CONFIG_TEXT: urlopen error [Errno 99] Cannot assign requested address

Cause

This error occurs when migrator tries to check connection to target host. It takes the first IP from IP_Addresses table and tries to establish connection. The problem is that the first IP does not exit anymore on the server.

Resolution

Go to Tools & Settings > IP addresses and click Reread on a target server. Repair or remove failed IP address.

If the issue persists, connect to the target server via SSH and make sure that all IP addresses on the server are properly configured and can be pinged/resolved.

Contact server's administrator or hosting support if any help required or if some options are missing in Plesk.