Have you logged into your Steam account and saw a black screen?
Some games contain not only game progress in the save files, but also graphics settings. When these settings do not coincide with the predefined ones, problems with video transmission may occur, as in the example below.
What to do?
Do not worry, this question is very easy to solve.
Do not end the session. Copy its identifier directly from the address bar of the browser and send it to support (chat in the lower right corner).
We know how to help you very quickly 🚀