There are no duplicates of this I found and I do not know if this is a known issue

The game is stuck here, showing the loading animation but the bar just stops. Happened 1 day after updating to MC v1.11 and not opening the game in between. 

I think these could have caused it: HelenAngel said it was the textures.

-A few worlds with a lot of command blocks, although they existed for quite some time

-Resource pack with 128x128 textures. Deleting most/all of them through the Files app didn’t do anything