I made a APK, prompts: the application is not installed

from my experience, this happens when you use the APK in the "objects" folder.

rename the temp.ap_ to << appname>>.apk. in the "objects\bin" folder. Install this version.

I am not to sure why this one works and not the one the "Objects" folder.

Hope this helps.

I don't think that the above suggestion will work.

This can happen for several reasons. Try to uninstall the package from your phone and then install it again.