Solved for me:
Running windows 10 on my computer (see below); I ran into this issue and couldn't install a hand full of apps through the Microsoft store, including the 'App Installer' which also prevented me from unpacking/installing some apps separately from the store.
Upon giving up, I decided to get windows 11 but needed to enable 'Firmware TPM' in my bios to qualify. After enabling TPM and before upgrading to windows 11, I tried the store again and it worked!
Here's how to enable TPM: https://support.microsoft.com/en-us/windows/enable-tpm-2-0-on-your-pc-1fd5a332-360d-4f46-a1e7-ae6b0c90645c#bkmk\_enable\_tpm
I hope this helps someone else out as well!