Something went wrong: error code 504

Hi ODK central community,
need help in central
Today I went to ODK Central as usual, uploaded the fic and made a small correction to the questionnaire after testing. Even when uploading the patched file I got this message (Something went wrong: error code 504). After that I hardly "do" anything. For the first 1-2 hours, I could not enter the central office, and apart from that, I could not perform any operation. Everything (after a few minutes of "thinking") shows this message.
How to check the correctness of the central parameters (there is an instruction somewhere)?

Here is the section of the docs on updating forms to a new version:

Read your logs. Any hints there as to what is going wrong?