Why do I get a message saying can't open file when try to open a download?

[theresahoward220]

After I download a file, I get an error message that says. Can't open file.

 

[LeoRex]

Depends on the file. If it is an APK that you want to sideload, your security settings most likely are set to not allow you to install it. If it is a media file of some sort, there may not be an application installed on your device that is registered to accept that file type.