Using snapshot 17w48a I have run into a bug where animations for orange and yellow glazed terracotta no longer seem to be functioning properly. This was not present in the official release 1.12.2 (though the yellow terracotta in that version DID inexplicably freeze on one specific frame. This may be unrelated but I'll describe it anyway in case this problem ties in somehow. In 1.12.2 Yellow terracotta would freeze on the 21st line of animation code--I could switch out the frame number, but in-game it would always freeze on that image for a good 5 frametimes despite code not telling it to do so). Anyway, back to the snapshot issue:

I have attached an example pack to help with troubleshooting. I suggest comparing the broken "yellow terracotta" animation code with working "black terracotta" (as both are fairly simple and short).

Things that are not causing this error:

• Number of pixels in the png file (it scales properly from 32x32 and the same animations were working in all previous versions).
• File name (the new 1.13 file names were copied directly from the snapshot jar files)
• I don't believe it's any errors in the animation code itself (because again, it was working fine before). But I did try rewritting the code just to make sure and it promptly broke again only about a dozen lines in.

That's the summary of the issue. Let me know if you need any further information.