The Microsoft Store is missing for some in the Windows Insider build 17110

Microsoft’s new Windows Insider build has an unforeseen error. Windows Insiders have quickly become aware of a bug that prevents the store app from working, rendering it useless.

Microsoft’s Jason Howard explains the situation in a forum post.

We launched build 17110 to WIP Fast this morning and have received a quick influx of feedback regarding the Microsoft Store application not functioning as expected. There are several experiences being reported:
Pinned tiles missing on Start
Missing pin from Taskbar
Application not showing in “All Apps” list / Start
Missing from Settings > Apps & Features

Insiders are warned not to attempt to reset the Store application, as this merely erases the Store app from the system without actually fixing the issue, potentially making it harder to recover from.