@Mahz see, that sounds really weird. Has something changed with the server host (assuming that you are not hosting privately on your own PC's)?
It all started when I upgraded the Guild's dependencies. I upgraded them all at once where I should've done the big upgrades by themselves so that I had more of a clue if there were regressions like this. That said, staying on old versions isn't a solution either, so hopefully keeping them upgraded (as soon as upgrades come out) will fix the regression if there is one.
@Mahz Could it be the new Dice system?
I doubt it, though there's always a possibility that a bug in the parsing library (github.com/pegjs/pegjs) gets stuck in a loop.
Since the same parser is run in the browser to validate your roll before you submit it, you'd think it would lock up the browser if there was an endless loop. I won't know til my CPU profiler tells me.