[Zubersoft]

So, it's not actually MobileSheets that is freezing. If you open task manager (Ctrl+Shift+Esc works if you have a keyboard), you will see that Microsoft's AuthHost.exe process is the one hanging. If you have a Surface Pro in tablet mode, you can drag from the sides of the screen to switch the active application.  If you kill the Authost process, MobileSheets will continue along just fine. The AuthHost process is used with the embedded web browser in order to complete the authentication with OneDrive. This is unfortunately not something I have control over, and I think Microsoft must have made changes to Windows at some point that caused this issue. It's important to note that the problem will not always happen - sometimes you can log in just fine. So you may just have to attempt it a couple times or you can kill the AuthHost.exe process.

Mike