Files App

You may want to try restarting the iPad, to do that, just click either the volume up or volume down button, and after doing that, hold on the top button till a slider appears on screen which says 'slide to turn off'.

To start it up again, hold on the top button till the device boots.

If the above steps don't help, try switching to a different network, possibly your phone's cellular hotspot and try downloading it.

Thanks for the screenshot - although it is such low resolution I can’t actually read it.

As best as I can tell, you might be attempting to install an App, from the App Store on your iPad. If this is the native Files App, an integral element of iOS/iPadOS, this might imply that you have previously uninstalled this App from the iPad?

Unable to install what files? What is the exact error message?

Can you post a screenshot?

Take a screenshot on your iPad – Apple Support

Start here:--> Use the Files app on your iPhone, iPad, or iPod touch - Apple Support

Regards

Giulio