WorkDocs - Inactive to Active not working

I have a External WorkDocs folder that was owned by someone who is no longer with the company. I have gained ownership of the entire folder structure and have admin rights. I am trying to change a user from Inactive to Active. I go into the Admin Console and every time select 'Active', I get a "We weren't able to update the user xxxxx@xxxxx.com" error. How do I change them to Active?