When going through a nether portal (Nether to Overworld), the game occasionally freezes. It happens most often if the game is autosaving or I'm holding lots of shulker boxes. 

If I wait for 10-15 minutes on the frozen screen, then I get a "communication error" prompt, then will continue thought the portal as usual.

If instead of waiting I force close Minecraft, it will tell me an error occured. If I rejoin the game, then on the title screen, a banner at the top says "Global resources reset - failed to load previously"

After this issue, there is a chance that I lose my inventory (it resets back to the last autosave, but the world doesn't). I have personally lost many many full shulker boxes to this.