Je ne sais pas de quoi vous parlez.
I originally put ce que, and I was wondering if ce que could still be right? What is the difference between ce que/ce qui and quoi?
You can't use ce que in this sentence, it would be wrong:
Here are correct sentences with translations, I hope they help you to understand the difference:
First two sentences are correct but ce dont is more elegant (and would be used when written), and de quoi is more common in conversations.
ce qui or ce quoi cannot be used in your example.