I am having the same issue. Installed forge 1.16.2-33.0.31 downloaded yesterday (sep-2-2020). only one MOD Xaeros MiniMap 20.20.3 forge 1.16.2.jar
I have two different computers, one it works with an error stating this is a beta but will let me continue. the other locks and does not cont to load at the Atlas Stitching: minecraft:textures/atlas/blocks.png
Any ideas?