You have a Windows 10 device that has not yet installed Cumulative Security Update KB3074683 or subsequent Cumulative Updates. This may occur if you purchase a new Windows 10 device, or installed Windows 10 as part of the Windows Insider Program.
Prior to installing Windows Updates, multiple user accounts are created and one user installs or updates an app via the Windows Store while the other users are not signed in.
The installed or updated app is available for multiple user accounts. Examples of such apps include Cortana and Windows Store.
In this scenario, the installed or updated apps may fail to launch for other users, and the Start menu will not dismiss.
Microsoft confirms this is an issue in Windows 10. This scenario creates leftover invalid entries in the registry, which causes a conflict when launching the installed or updated apps. Cumulative Security Update KB3074683 or subsequent Cumulative Updates, installed automatically when upgrading to Windows 10, includes a fix that prevents the issue from occurring. However, new devices that are pre-installed with Windows 10 may not have installed these updates when the user first signs in. Installing the Cumulative Updates will not resolve this issue after you have already encountered it.
Microsoft has created a troubleshooter to resolve this problem.
To fix this issue automatically, follow these steps: