I have in the past change my rendering system but, I did not after the glitch.
Yes, I do have mods installed such as ENB [Wasn't enabled at the time, too laggy] and, some textures + animations is really all. Oh yeah, a interface and podium as well.
Not after the glitch, no, I have not tried reinstalling mainly since it has not happened yet, again. It's just something I found very odd. I might reinstall if it does it again.
Yes, it is a VERY weird glitch.