I don't yet have over 2000 rep on Stack Overflow so I can't edit at will there. At this moment I have 26 approved edits and 1 that's been rejected, so I think my account is in good standing. However, there are certain questions for which the edit button is not available, whatever I try.
Maybe it's because someone else is already editing them, I don't know, but it's incredibly confusing. I'm forced to keep double checking to see if I still have the right to edit. I tried refreshing some questions in the hope that the edit button would magically reappear, but nothing happened.
Why not show me the button, but have it grayed out, with a message explaining why I can't edit the question? Otherwise, it's just going to frustrate me, and probably others that are in my situation.