Installation fail on build and run

I get the following error when I try to build and run to my android device:

UnityException: Unable to install APK!
Installation failed. See the Console for details.
UnityEditor.Android.PostProcessAndroidPlayer.ShowErrDlgAndThrow (System.String title, System.String message, System.Exception ex)
UnityEditor.Android.PostProcessAndroidPlayer.ShowErrDlgAndThrow (System.String title, System.String message)
UnityEditor.Android.PostProcessAndroidPlayer.UploadAndStartPlayer (System.String manifestName, System.String stagingArea, UnityEditor.Android.AndroidDevice device, System.String packageName, Boolean devPlayer, Boolean retryUpload)
UnityEditor.Android.PostProcessAndroidPlayer.PostProcessInternal (BuildTarget target, System.String stagingAreaData, System.String stagingArea, System.String playerPackage, System.String installPath, System.String companyName, System.String productName, BuildOptions options)
UnityEditor.Android.PostProcessAndroidPlayer.PostProcess (BuildTarget target, System.String stagingAreaData, System.String stagingArea, System.String playerPackage, System.String installPath, System.String companyName, System.String productName, BuildOptions options)
UnityEditor.Android.AndroidBuildPostprocessor.PostProcess (BuildPostProcessArgs args)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, System.String downloadWebplayerUrl, System.String manualDownloadWebplayerUrl, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:316)
UnityEditor.HostView:OnGUI()

How do I fix this?

Player Settings → Install location / Set it to Automatic

Go to Settings > Apps > Your app name and at the top right click settings and click “Uninstall for all users” ----- then try to install your apk again, that should work.

The problem is that the app is still installed on your device but not for current user, thats why its not visible for you, if you change the user in the settings the app will appear. Unity could not install the app over the old one.