The Import Software Licenses completed with error
To resolve the issue that you are getting, you will need to allow a complete migration by logging to into Plesk, and after that you can edit the sub-domains that have got a unique FTP users.
After that you can set them to "Use the FTP user account of the main domain". Once you have set all the of the sub-domains to use the parent domain's FTP user account, the PMM migration that did not work will have to be removed from the PMM page, and after that the migration will started over.
The new PMM migration will work well, that is if all the sub-domain FTP users have been set to use the "main domain's" FTP user.