I'm voiced in the Karaoke, Mp3 and realm-Albums channels but can't see any ads or communicate with others (or bots). I've been in these channels for months and didn't recieve any error messages. This just happened last week. I didn't install any new software.
I do see messages like the following but don't see any user ads:
Regardless, your problem is still not related to mIRC (unless you have some script hiding the text). Use a clean copy of mIRC if you suspect a script is the problem.