Hi Zorin ,

Try this steps

Method 1

 Perform Clean Boot

1. Open run box press Windows button + R
 2. type MSCONFIG
 3. Under General Tab select Normal Start up
4. Go to Services Tab then check Hide all services box .
 5. click Disable all then Enable all
 6. Click Apply then  OK

7. Restart

Method 2

1. Open Elavated Command Prompt
2. Type WSRESET
3. wait untill it open Windows Store then restart the computer.

Method 3.

1. Uninstall all the Windows Store apps that are not working
2. Sign out your Microsoft Account on Windows Store app
3. Run WSRESET on Elavated Command Prompt
4. Re Download all the apps , Enter your Microsoft Account when it ask.
5. then check if all the apps are still not working .

Method 4 (Updated by Moderator):

1. Search for Windows PowerShell using Cortana or Windows Search.

2. From results, right click on Windows PowerShell and select Run as administrator.

3. Then type following command and press Enter key:

Get-AppXPackage | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

Let the command complete.

4. Close Windows PowerShell and see if the issue is resolved now.

Method 5 

You can also try to create a new user account

1.Swipe in from the right edge of the screen, tap Settings, and then tap Change PC settings.
(If you're using a mouse, point to the lower-right corner of the screen, move the mouse pointer up, click Settings, and then click Change PC settings.)

2.Tap or click Accounts, and then tap or click Other accounts.
3.Tap or click Add an account, and then tap or click Sign in without a Microsoft account (not recommended).
4.Tap or click Local account.
5.Enter a user name for the new account.
6.If you want this person to sign in with a password, enter and verify the password, add a password hint, and then tap or click Next.

If your PC is on a domain, depending on the domain's security settings, you might be able to skip this step and tap or click Next, if you prefer.

7.Tap or click Finish.
8. Login using the new user account then redownload all the apps.

Method 6.

Perform In Place upgrade
1. Download Windows 10 ISO file on this link https://www.microsoft.com/en-us/software-download
2. Run the Media Creation Tool then follow the set up
3. Save the Windows 10 ISO file on your desktop
4: Right Click on the file then Choose Open With Windows Explorer
5: Follow the set up.
6: Wait untill it goes to your login screen or Desktop screen.

Please let me know if this helps

Cheers

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Note: Microsoft has updated this reply with more information in interest of users facing this issue.

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