I can't install Microsoft apps

Hi, welcome to tenforums.

Could you explain exactly what you clicked on to get that message?
And does Firefox work normally otherwise as far as you know?

When did you first notice this? Was this Windows installation working normally before this?
Were you previously able to get apps from the Store (that one's not a MS app...) and install them?
If so, what change might be related to this problem?
Some clues as to recent history might help.

What is your Windows build?
Windows key + R, winver

Thanks!

sfonseka said:

I was previously able to get apps from the Store. Now app store is disappearing too.

If all the built-in apps including the Store have stopped working, try this tutorial.

Reinstall and Re-register Apps in Windows 10 | Windows 10 Tutorials

I just downloaded the program from Softonic and installed, seems fine.
My version of Win10:
Attachment 200260
On a new computer I set up for a lady last week I'm seeing issues with her Win10 S mode and programs NOT from the Store.

Berton said:

I just downloaded the program from Softonic and installed, seems fine.
My version of Win10:
Attachment 200260
On a new computer I set up for a lady last week I'm seeing issues with her Win10 S mode and programs NOT from the Store.

Don't download anything from that site. Seriously, if you don't want something extra that will come with your apps.

Berton said:

On a new computer I set up for a lady last week I'm seeing issues with her Win10 S mode and programs NOT from the Store.

Isn't the whole point of S Mode that you can ONLY use apps from the Store?

AndreTen said:

Don't download anything from that site. Seriously, if you don't want something extra that will come with your apps.

Didn't get anything extra, have never had a problem with the site.

Berton said:

Didn't get anything extra, have never had a problem with the site.

Maybe they changed their policy, but read this in the meanwhile...

blog Malwarebytes | detections/pup-optional-softonic/