I see folks complaining on Discord, and also in OpenAI's discussion forum:
https://community.openai.com/t/gpt-4-has-no-response-then-something-went-wrong/135226/134
It seems OpenAI has not reflected on the issue so far, and does not respond to support messages. All of OpenAI's services are operational, at least officially.
From Discord it seems that the issue is not confined to a specific geographic area.
Does anyone have a clue on what is happening? Is it just a badly handled capacity problem, or something else?