Sharing lock occurs when managed package is inactive

When a managed package is no longer active, a System Admin can make sharing changes but sharing recalculations will fail resulting in an unreleased sharing lock. This can also occur when any licenses associated with the managed package are disabled, or expired.

This occurs because the user making the change no longer has access to the entity being recalculated.

Subsequent sharing changes will fail with the following error due to the lock:

"The sharing calculation you requested can't be processed right now, because it interferes with another operation already in progress. Please try again later."