Unable to start migration: Unable to execute command because another migration is in progress

Renan Poss Moreira

Updated January 13, 2026 19:14

Plesk for Windows kb: technical ext: migrator ABT: Group A

Applicable to:

Unable to start a migration at Tools & Setting > Migration and Transfer Manager. The following message is shown in Plesk Migrator UI:

PLESK_ERROR: Unable to execute command because another migration is in progress
The "Starting a migration" step is hung.

Possible causes:

Another migration process is running.
Plesk Migrator processes are stuck.
Temporary files left after previous processes. Temporary files can be present if the process was crashed or "killed" by a user and thus a cleaning up was not performed properly.

If there is another running migration session:

Log into Plesk
Go to Tools & Setting > Migration and Transfer Manager
Stop all running migrations or wait for the current subscriptions migration to finish
Re-run new migration session

If there are no currently running migration sessions:

Log into Plesk
Go to Tools & Setting > Migration and Transfer Manager
Stop all running migrations and remove all sessions by clicking the Finish migration button
Connect to the target server via RDP
Remove or move out orphaned directories from previous migration sessions:
4.1. Open File Explorer and navigate to the directory %plesk_dir%var\modules\panel-migrator\sessions
4.2. If there are any directories inside the directory sessions remove or move out them
Kill all possibly hanging processes:

C:\> taskkill /T /F /IM python.exe /IM rsync /IM paexec.exe /IM MailMigrator.exe /IM pmmcli.exe
Open Plesk > Tools & Setting > Migration and Transfer Manager and start a new mitigation.