I have the same problem on three computers that I upgraded to the Creators Update.

On one of the computers, something has gone wrong with the Mail app.

One of the user accounts the Mail app...

I recommend that you repair Windows 10 with an Inplace-Upgrade as this is the easiet way ro resolve the issue with not being able to install apps from Windows store.

Instructions can be found...

I used Get-AppxPackage | Select Name, PackageFullName in Powershell, but it didn't list the Insider Hub and Windows Feedback apps.

This seems to confirm that both apps have been uninstalled, but...

I'm using a German version of Windows 10, so I'll only make the revelant screenshots so that you can see what I'm referring to.

115885

115886

115887

As these app are not listed in Apps &...

I tried to uninstall the two Apps using Powershell, but the Insider Hub and Windows Feedback apps couldn't be found.

Seems like they have already been uninstalled, but are still showing in the...

Thanks for letting me know about this tutorial.

I used the tutorial to reset the Messaging app and now the first entry has vanished from the notifications list.

I couldn't find the Insider Hub...

Under System - Notifications & actions - Show notifications from these apps I have three entries that have no symbol and a strange looking name.

115750

I noticed these strange looking apps...

Hi Koen,

I'm having similar issues with the Windows Store and the camera app, and apps like calendar, mail, onedrive not working for all users.

The issues started after patch Tuesday in January...