Scope: Prime Mover Free


This issue only affects users of Prime Mover Free in Windows operating systems. This is due to the fact that Windows limits the number of characters in the path with a constant known as MAX_PATH limit.

You will get this error if the website under migration has some very long file paths. Usually you will get this if you have a plugin with git folders or vendor folders which is deep nested. This results to very long file paths.

Windows OS Workaround

Temporary Plugin Workaround

If you have done above, the next thing would be apply a temporary plugin workaround.

  • In your Windows OS, go to C:\ root drive and create folder named as pm_tmp
  • Open your favorite text editor and copy the code below :
Plugin Name: Prime Mover Windows MAX Path Limit Error Workaround
Plugin URI:
Author: Codexonics
Version: 1.0.0
Author URI:

add_filter( 'multisite_migration_filter_basebackup_dir', function( $path ) {

//This will create and use C:\pm_tmp as the temporary backup tmp
return 'C:\pm_tmp';

  • Activate that temporary plugin in your site.
  • You can now proceed to export / import using Prime Mover Free version.

Permanent Fix

The above plugin is just a workaround for Windows MAX Path limit error. The recommended permanent solution would be to use the PRO version which allows you set a custom base backup directory directly inside Prime Mover.

It looks something like this (temporary plugin is no longer needed and should be deactivated)

As you can see, the custom backup directory is permanently set to use C:\pm_tmp. Since the directory is placed on the Drive C root directory, the paths will shorten.

If you still see errors after doing this fix (permanent or the workaround), then the issue is in your site paths. It might be too long that its affecting portability between operating systems.

Was this article helpful?