How to Fix Windows 10 Calculator Error “You’ll need a new app to open this calculator”

Try this first – Solution 1

Run the troubleshooter:

Select the Start button, and then select Settings > Update & Security > Troubleshoot.

And then from the list select Windows Store apps > Run the troubleshooter.

Solution 2

1. Press the Windows key + R to launch the Run dialogue box.

2. Type Wsreset.exe and press Enter.

Solution 3

Delete the regkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Appx\AppxAllUserStore\[UserSid] Restart