When this bug appears, I was playing in a 1.9 serv with WorldEdit and VoxelSniper.
Then, my chara suddenly avance, like the Z ( I'm playin with Azerty keyboard ) was blocked,
I couldn't acess to the menu or inventory, and I couldn't move the camera too.
so I do Alt+F4, and restart my game...
But the bug was alway's here and this time I was blocked on the menu.
sometimes later the bug was no more.
But this morning, the bug reappears.
I thought it was a problem with forge or LiteLoader, but after a complete reinstallation, the bug was alway's here.
And the worst, is that I was thinking it was only for 1.9 but it does this with all my version of minecraft.

Apparently, minecraft failed to launch GPU.
I have Sucess to fix it by lauching my game as administrator.