Zandronum

Considering Zandronum came with this, I assume this goes here somewhere...
I can't join any online game, because apparently all the required things I download are incorrect, as I get random error messages every time I try to join. Code problems from the wads and pk3's that I have no idea how to fix. This is very vague, so I understand if you have NO CLUE AS TO WHAT I AM TALKING ABOUT. I hate Zandronum so much right now because the one defining feature about it doesn't work.

This is too vague. If you want to be helped, you should try to provide the error messages or, at the very least, make a screenshot of the problem.