As FunFuntomes said, that's the test version which shouldn't get posted here. Besides actual bugs they are usually missing some bits; the dev straight up said this one is missing an animation and has placeholders for some things. Higher-tier supporters get the test builds and find stuff that got past QC.3.50 is outt
X.x0 versions are test builds.
X.x1 are the "stable" builds, though there's usually a few things that still slip through.
X.x2 are "patched" builds that include fixes and sometimes tweaks; X.x1 doesn't always get an X.x2 (3.41 didn't get a 3.42).
X.x5 are "small updates" if there's some stuff to add but not enough for a full update. Usually things that were orginally meant for X.x1 but weren't included for some reason. Plus any outstanding fixes/tweaks. 3.15 was a small update to 3.11. There aren't many X.x5s.