I downloaded an APK and when I try to install it, the "install" button is completely unresponsive.
I have gone into the settings and enabled "Unknown sources" in the security section.
Is there something else I need to do?
I'm using a Galaxy S5 with Kitkat 4.4.2, unrooted.
Disable your screen dimming app. :)
Some screen dimming apps work by overlaying the whole screen with a translucent window, and letting touch events pass through to the activity below, but for security reasons, you can't interact with system dialogs (such as the package installer) through another activity.
It sounds counter-intuitive, but it could be the cause. It's more likely than a corrupt APK file or a version incompatibility, either of which would cause an error message.
Try to install it using adb. Download the Andorid SDK and then connect your phone to the PC via USB, make sure the USB Debugging option is ON under Developer Option in your phone settings.
Once you are done try to use these commands. adb devices to check the connection to your device and then if everything is OK try adb install <filename>.apk. Make sure you input the correct path to the file or simply copy the apk into adb directory.
adb usually resids into adt-bundle-$version/sdk/platform-tools
You can command prompt cmd in Windows or console in *nix based system.
Disable Verify Apps in Security. If that didn't help, you could just copy the apk file to /data/app/ and reboot the phone (as a temporary solution), also try Wiping the Dalvik Cache.
if you received a warning,then Google can and does block apps that can be damaging,and or have malicious code in them. Google can even remove apps after installing as well. Find and read their policy on installing apks from other sources.
