This has been happening for the last three 1.14 betas, and it seems to be worse with .0.6.

My game is crashing frequently. there isn't a pattern with what i'm doing - I could be flying, I could be placing blocks, I could be walking somewhere, it doesn't seem to matter. There's usually  a brief (1 second or so) freeze and then crashes to desktop. 

just before this report it crashed twice within the space of two or three minutes

EDIT: This happened up to 0.50 frequently. Then with 0.51 it was fixed. I didn't have a single crash or freeze. Upon loading my world for the first time in 0.52 however, I got a couple of minutes in and it crashed. loaded the game up again and it froze on the menu screen causing me to have to restart my pc to get it to work again. 0.51 fixed it, 0.52 broke it again