I am having an issue trying to delete an obsolete user. For some reason, even though the user no longer has posts of any kind, deletion under the Network admin user delete doesn't do anything.

Since I had used this user in the setting up of wpforo in the early stages, I'm thinking the plug-in may be 'holding on' to that user. I have tried to do a network deactivation, I've filled in the response form, but nothing happens.

How do I do a network deactivation, then? (It's a multisite.) Use CPanel and move the plug-in? maybe uninstall and clean install would be the thing to do (forum still nearly empty) but as I can't deactivate I suspect I won't be able to uninstall either....