There it is. Quite unexpected. I'll make no further estimates about how many more versions there will be before the public Steam release ;-). We broke memory management internally in R54 in certain situations which might have been responsible for all kinds of crashes. And it broke skill usage under certain circumstances. As usual the change log is here, you can get the non-Steam version via prerelease access and you already have a code if you are an eligible member of the original crowdfunding campaign.