The chat has been stable for the past ~2.5 days, so I'm pretty optimistic... let me know if there is a problem with it again.
To give context as to what happened, last weekend I did a major upgrade to the software the site uses (not the code I wrote, but rather the dependencies (other software) used by my code) and the existing chat code no longer worked after the update. As a result, I had to replace parts of the chat code. Both the old and new versions behaved unpredictably sometimes, but I'd had years to work around the behavior of the old version, while the behavior of the new version was new. As a result it took a few days of trial and error to get it under control.
Is chat crashing constantly for anyone else?