|Error: You have no permissions on this plan|
Check that the Plan for the end user account in question has full permissions set.
Go to Plans tab:
If next to the lock icon for the Plan in question is the text: FULL - it means no issue.
If FULL text is missing then there is a permissions restriction in place.
To grant full permissions:
click on the lock > unselect all checkboxes > commit changes
Full plan access should now be restored and you can resume suspended accounts, etc.