An hour ago I found this question, and ended up just adding a comment to it, since it didn't seem to me that it was complete enough for posting as an answer.
However, the OP apparently thinks otherwise and replied «This is an excellent response. Consider making it an answer.»
The question seems to have been protected in the meantime. The only message showing is
Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site.
and I see no answer form.
I do have more than 10 reputation, albeit only from the Association Bonus.
Half-way writing this question, the Similar questions bar showed me 100 reputation, yet cannot answer protected question(reputation > 10), which is the exact problem, but at that time the message was slightly different:
This question is protected to prevent "thanks!", "me too!", or spam answers by new users. To answer it you must have earned at least 10 reputation on this site.
The key words there were earned on this site, as remarked on the other answer for the other question. That's still not ideal, and there are a number of suggestions for better wording on Improve “Protected Question” message with regard to rep gained through Association Bonus (meta), but still better than the current one. The wording of the current message should be changed to take the (ignored) association bonus into account.