This is repeatable on my machine, If I go through a portal, and then return fairly promptly, I get stuck in the 'generating terrain' screen. The game keeps running, (I was starving in one attempt and kept starving), but the screen stays up and I have to close and restart minecraft.

The grabbing stuff from the chest in the video wasn't a part of the sequence of events, it was more of a timing spacer - returning within 20 sec or so triggers the crash. Sometimes it takes three trips to happen, but usually it's two.

Further note, not very repeatable but with an underground portal, if you quit out whilst in the portal and reload, as I had to do a number of times testing this, you may occasionally spawn in on the surface directly above where the portal lies. Far less common, but memorable and slightly distressing, you may spawn in directly under the portal.