I have a similar issue where MCD store app does not open. To workaround, I've had success by going to MCD app settings and clicking 'Terminate' to force-close associated processes. Then MCD app can start. However, after playing and quitting back to desktop, I notice the splash-screen launcher is still open/stuck with error 'error launching game', and after closing this, I am back in the 'app does not open' problem again and need to Terminate again to workaround.
I have a similar issue where MCD store app does not open. To workaround, I've had success by going to MCD app settings and clicking 'Terminate' to force-close associated processes. Then MCD app can start. However, after playing and quitting back to desktop, I notice the splash-screen launcher is still open/stuck with error 'error launching game', and after closing this, I am back in the 'app does not open' problem again and need to Terminate again to workaround.