He's talking about when you're not using a script. If you just add people to your auto-op or auto-voice list, mIRC will automatically op/voice them as long as /avoice and/or /aop is turned on without the need of a script. But, if you're not an op, you'll get errors and you'd have to write a script to avoid that.
I agree that mIRC shouldn't try to auto-op or auto-voice anyone if you're not an op and shouldn't give any errors, either. I've not tested it, but apparently it's trying to do both things.
