'App not installed' error on Android

One way to get this error is to try and install incompatible APK for your phone. v7a vs v8a vs x86. Are you getting the error on every software? Even on updating existing ones from the place you installed them from? Is this on the main profile? I don’t know what this might be, but going through some diagnosing steps might help. There’s also “View logs” in System. A lotta stuff that is not easily read but we might get more information on the problem we’re dealing with