Support Plugin Category Issues

OK the problem I am having in my multisite is that for some reason on certain sites, the default support category is blank, so then when someone attempts to add a ticket, there is nothing for them to choose in the category drop down, so then when they try to submit their ticket, they get an error saying they must select a category, when they have no way to do so.

The other problem is, I am unable to add custom categories in the network admin / support area. It is simply not accepting them and it just remains blank. I tried adding them in the database directly but kept getting an error that the category field can't be identical to another field (which doesn't make sense if you want the default category to be "General" for every site in the network.)

Anyway, I really don't need categories anyway. Can someone tell me how I could edit the plugin file code in order to simply get rid of the category field / functionality altogether so that I don't have this issue?

Thanks.