Hey, so everyone seems to be having the same issue and it's scattered across multiple threads, so I figured I'd make one with the info in the main post. Seems to be some sort of bug with Morph right now that's causing the game to crash on startup.
You can fix this temporarily, if Morph isn't that important to you, by simply removing it until it's been properly fixed. Either open the start menu and type "%appdata%" into the search bar, or go to C:/Users/<your name>/AppData/Roaming/.technic/modpacks/attack-of-the-bteam/mods and remove the "morphbeta-0.6.0.zip" file. This will allow the game to startup, but I DO NOT know what will happen if you load a world where you were logged off in a morph. Use at your own caution!
EDIT: As veggteppey has said below, it seems that setting your Technic Launcher to "Use Beta Builds" (click the cogwheel in the top right of the launcher) also fixes this issue! This issue seems to be solved in general, according to some people, and might be fixed.