Migration Manager fails to overwrite domain's files on a destination server: Rsync failed to copy files from the source

Symptoms

• Target server already has the same subscription, but with different file set;
• Migration fails with the following error in the GUI:
  

  PLESK_ERROR: Error: Failed to copy web files for subscription 'example.com'
  Migration tools tried to perform operation in 3 attempts: Rsync failed to copy files from the source (the source server 'source' (203.0.113.2)) to the target server (target Plesk server):
  This could happen because of a network connection issue. Run migration for that subscription once more.

• An error could be found in debug.log of migration:
  

  CONFIG_TEXT: +|2017-09-08_06:43:15,805|D|ST1|core.runners.base|example.com||Execute command on the local server: C:\plesk\var\modules\panel-migrator\sessions\20170712000000\target-server\rsync\bin\panel-migrator-rsync.exe --no-perms -t -r --inplace rsync://admin@203.0.113.2:10156/vhosts/example.com/ /cygdrive/c/Inetpub/vhosts/example.com --exclude /statistics --exclude /subdomains --exclude /.Security
  +|2017-09-08_06:43:24,680|D|ST1|core.runners.base|example.com||Command execution results:
  =|2017-09-08_06:43:24,680|D|ST1|core.runners.base|example.com||stdout:
  =|2017-09-08_06:43:24,680|D|ST1|core.runners.base|example.com||rsync: open "/cygdrive/c/Inetpub/vhosts/example.com/httpdocs/somefile" failed: Permission denied (13)

Cause

rsync is unable to resolve conflict between already existing and new files.

Resolution

All the following operations must be performed on the destination server:

1. Login to Plesk.
2. Optionally, create a backup of existing data in Tools & Settings > Backup Manager :
   • Click on ' Back Up ';
   • Choose ' Full' backup and click ' Ok '.
3. Remove subscription(s) that fail to migrate in Subscriptions > example.com :
   • Select the subscription(s);
   • Click on ' Remove ' and agree.
4. Restart migration process for removed subscriptions.