At one point I decided it was time for me to contribute by answering questions.
I sorted by new in PHP and found a brand new, really confusing & poorly written question. After about 5 times reading it through I finally understood what they needed, and wrote a full answer along with corrected code that I had tested.
Got an error when I submitted my answer that the question was locked. Just before I submitted my answer, a mod had locked it because it was a low quality question. I wasn’t allowed to submit my answer to their problem.
I haven’t tried writing an answer since. Just felt like a massive slap in the face for trying to finally contribute.