If you have multiple user accounts in Windows 10 and you have installed some Universal apps for all users, you may face an issue that such apps do not start. While the apps work for the user which installed them, they may fail to launch for other users, and the Start menu cannot be dismissed. Here is what to do in this case.
Microsoft had rolled an updated build 10041 of Windows 10 and made it available via Windows Update. There is no ISO image available for download, so interested users need to refer to Windows Update as described HERE. Users who have already installed it face the issue that Mail, Calendar and People apps are not opening in this build. Here is an official fix courtesy of Microsoft.