What the title says.
I just got my second, well or actually third arena key but I had used the first a while ago already, so the second key was in my stash Tab 6. I tried stacking them together which didn’t work, and then put the third key right below the second one (which was in top right corner of that stash). Then I proceeded to click my first stash which was full of all kinds of idols, and while the game still showed the 6th tab (where there were only the two arena keys), both the game and the computer froze.
I tried waiting for it for a minute or two to no avail, and since ctrl + alt + delete didn’t work, I resorted to shutting down my computer via the power button, which worked.
Also, when I restarted the computer, steam was laggier and my reviews and friends list were both empty, when there used to be stuff in both of them. Maybe you might want to check your steam forums too, at some point, just because they too seem to be a bit more bugged than some other steam forums I’ve visited: they sometimes ask for your consent to proceed due to possible NSFW-content each time you click open a different topic there.
Thanks!