When I was spawning Spiders in for Iron Golems to fight, all of a sudden the Spiders and Iron Golems were frozen, but I could move around, then it started hitching then it kept going, then the hitching got worse, then it crashed. But when it crashed it did not just crash the game it crashed my PC! I could not even open the CTRL+ALT+DEL menu. I tried loading up the world again then it crashed my entire PC. I just booted up Minecraft to check the version number for this report, then closed the game, then it crashed again. Seriously Microsoft?!?!? This got past CERT? Please fix ASAP! World file below:

1.4.0.5 EDIT: It does happen in 1.4.0.5, but not as frequently, only happening when you exit the game, create a new world, and sometimes load new menus.
1.4.2.0 EDIT: It still happens, but even less frequently, only happening when launching the game and quitting. The Game still crashes PC when quitting the game. It seems to happen because of a program called "Service Host: Web Account Manager" that opens every time Minecraft for Windows 10 opens. Presumably for Xbox Live activity, Marketplace, Severs, World Joining, etc.
1.4.2. (2) EDIT: It happens even more now! Ignore the last two updates as those are nowhere close to how much this game crashes, this edit is more like the original post
1.5 EDIT: Still crashes on the home screen, jitters cursor when moving, then when the cursor moves too much it freezes for 15 seconds then crashes PC.
1.6 EDIT: Still happens, although a new issue was opened for this: https://bugs.mojang.com/browse/MCPE-36274