I have a MSI GP62MVR-6RF with an MSI MAG241C as external display (with Displayport, so I can use G-SYNC). I used drivers 430.40 until last week, when after rebooting I couldn’t get in the GUI environment. After double checking all the config files, (look note 2 in this thread), the only way I could make it work again has been by installing the new version. There are some changes to the post-install script that had to be made, since the swupd --fix command wasn’t properly formatted (refer to the official guide to get the right command). I can only say you should really double check all the configs and the symlinks, because it’s easy to miss something.