I'm trying to get on the beyond server with the MyM launcher but minecraft doesn't even open. The status window goes for a bit then stops and the launcher comes back up. I was able to get on the server just fine through the Twitch launcher. Here is a link to the latest crash-report any help is greatly appreciated.
Update your graphics drivers. If you've recently updated them, then downgrade instead. That only the MyM launcher causes this issue, indicates that one or the other launcher likely uses an integrated GPU. You should try and make sure that all your launchers use your dedicated GPU.
I was recently having this issue because windows 10 decided to change my video drivers. Had to reinstall them. Also happens when I have more then 3 instances running at once as my computer will then decide to use the integrated video instead of the Video Card.
I just tried again today, i was still having issues with it loading from the launcher but realized i had for got to up the amount of RAM java usues in the options for the launcher. i did that and it seemed to help.