I don't know why (and I don't care) but this did the trick. I spent over 8 hours trying to figure this out on my own and got your answer in less than an hour after posting here. I knew SOMEONE had run into this before.
It's not a limit, it's a really stupid message designed to help, and with some strange ways of guessing (yes guessing) if it is a form. Buttons mean form fields, at least to the programmer who created the test. (Trying to help is good; putting out messages which may be wrong and can't be turned off is very bad, because it leads to confusion, bad impressions, and a support burden on the creator; this is not even the worst example).