Well, mine had started working again. I t seems like it's something with that Join Files folder. It finally showed back up in my Drive and that's when everything worked. I deleted it again, just to see what would happen, after installing this version and the 404 error happens again. And deleting the folder in Drive de-authenticates the Chrome extension as well. Soooooo, could be that I'm just an idiot for deleting the folder. When the original beta broke stuff, I deleted the folder and uninstalled everything to start over. Seems like deleting the folder causes the 404 error. Join won't recreate the folder by default. Seems like it just keeps looking for it instead of creating it if it's not there?