I have more than 2000 reputation but it tells me that I'm not allowed to use Chat. What to do ?
It gives me , this:
Welcome to The Stack Exchange Network chat! You'll need 20 reputation to talk here. This site is moderated by the community, so please be respectful of your fellow The Stack Exchange Network users. And while you're at it, check out the FAQ!
chat.stackexchange.com
is a "separate entity" (by SE reckoning) frommath.stackexchange.com
. It is possible to be logged into MSE and not into chat (you may notice this also if you have associated accounts on other SE sites which you don't use as frequently). $\endgroup$