Classified Maker : Category missing (Change Category)

I've set up all of my categories and had no issue until recently. After a few more changing I've begun getting the error :  Category missing (Change Category)

I know I have everything set up properly, and am fairly certain this is a software error.

I've tried to delete the plugin and reinstalling but am still getting the error now. There are, I'm sure, lingering files that need to be deleted for a fresh install.

Please advise, and be aware that it was working fine but now it is now. I do not know how to reproduce the error, but it may have something to do with the update button on forms.

Please advise.