while walking up ther mount, I went prone and I glitched and fell through the mountain and into a lake. I quickly logged out hopping I wouldnt drowned in the 15 secs. When I logged back in, I was still on top of the mountain, drenched and every time I tried to walk down the mountain the jumping action started and the landscape started to flicker, I thought I'd fall through again. but walking up the mountain seemed not as unstable. So I just logged out and hopefully later it won't still happen again. fingers crossed.