There isn’t much information available about Tinder Error 40303, but it seems to be a problem that is affecting a lot of users. It’s not clear what is causing the error, but some people are saying that it happens when they try to log in.
It’s possible that this is a problem with Tinder’s server, or it could be caused by a problem on the user’s end. Unfortunately, there isn’t much that can be done except to wait for Tinder to fix the problem. In the meantime, you can try using a different dating app or website.