It used to happen all the time, and I began to suspect the site was doing it to themselves due to a large tournament not meeting its guaranteed prize pool amount, which means the site has to cover the extra out of their own pocket, giving them incentive to come up with an excuse to cancel the tournaments.
For a long while, this problem completely went away. It had been a few years and ACR upgraded their software so that it was no longer a piece of crap, nowadays their software is superb, state-of-the-art for the most part...
...and in all honesty, I don't think they are the culprit. For one, they have gotten much better at re-starting tournaments when the site does crash... which means my theory is obviously incorrect and false. But the fact remains, these crashes should not be happening and it is definitely maddening when they do occur... and its not just you - for whatever reason they HAVE been happening all too often lately. The site never explains why, but their popup messaging has gotten better over the years, at least they do keep us updated as best they can. In the distant past, there was no message at all, we were simply left to hang in the wind.
So while it is odd that this problem has cropped up yet again after going away for so long, at least there are some positives such as the effort to re-start the suspended tourneys instead of just cancelling them, and also their messaging is pretty good. I guess it's just something online players will always have to deal with. For myself, I usually take the day off if my local weather is bad, since I live in the woods and there is always a risk of a tree branch taking out the local power lines. LOL In such a case, there's no refund, I take the loss all on my own. At least when the site crashes, there is a refund policy in place if necessary. But not for local issues, so I'm always aware of the local weather when I play, especially in winter.