[MC-145513] All textures missing - fell to altitude 0.8 (no death)

I rode a tamed horse around and found that textures were missing at an edge of the map (about -800, 200; nothing peculiar). I tried riding through where the textures were missing, i.e. seemed like I was flying. Let me add that it was not possible to dismount the horse either, including before I entered the "missing textures" field.

I rode the horse a bit back and forth, before I tried to turn back and get to my last position. I believe I got to where the textures were supposed to be, but they didn't turn back on.

Suddenly I dropped altitude and it didn't stop until I reached 0.83 - all the while pretty much all textures were missing.

At that low altitude I could ride the horse freely around, no obstacles.

I've attached a range of images and the report after I manually crashed the game.

Best Regards
Lars