Installing applications from an unknown source does not work

I have been an avid Android user since the beginning. I like Android because it allows me to customize with my phone as much as I would like. This past weekend, I decided to try a new launcher on my Samsung S3. The primary driver for this was because the native launcher, TouchWiz, was often sluggish and on occasion crashed. I had heard good things about a launcher called Nova so I decided to give it a shot.
I must admit, the Nova launcher is snappy! The only thing missing was the date/weather application that TouchWiz had natively built-in. To address this, I decided to install Weatherbug. A long time ago, I scored Weatherbug Elite from the Amazon Appstore for free. As such, I went to the Appstore and attempted to install the application. Everything went well until the dialog box came up asking me if I was ok with application permissions requirements. On that screen I had two options: Cancel and Install. The Cancel button worked as expected, but the Install button did nothing. The Install button did not highlight like the Cancel button did when I pressed it. No matter what I did, I could not get the Install button to function.
What was going on and how can you fix it?


As you probably know, any application installed outside of Google Play is considered an “unknown source”. By default, unknown sources are disabled for security reasons. To enable unknown sources, navigate to your phone settings, go to security, and select the unknown sources option.
screenshot
Installing the Amazon Appstore requires the unknown sources option to be enabled so I knew that unknown sources had been working in the past. Just for fun, I decided to disable and re-enable the unknown sources option, but this did not appear to help. I also restarted the phone on the off chance that applying the Windows fix (when in doubt, restart) would fix it to no avail. Next, I went into the application manager, found the Amazon Appstore application, and tried to clear the cache and later the data options. Neither solved the issue. Based on the findings, I decided to uninstall the Appstore application and then re-install. During the re-install I ran into the same issue where I could not install the application. At this point it was clear that something had changed.
Coming from an operations background, it seemed logical that something had changed on the phone and that change was causing my problem. I mentioned earlier that I like to tinker with my phone. While that is true, I typically go through waves of changing settings and leaving the device static. At this particular juncture, I was just starting a new tinker phase so I knew a configuration change was unlikely. Another thing I typically do is install applications. I am an application junkie. Based on this, it seemed logical that a new application I had installed or an update to an existing application was causing my issue.
Do to the sheer number of applications I had installed, I deferred to Google for some assistance. The first search returned an article pointing to an issue in the TalkBack application. I went through all the steps outlined, but the issue remained. A second search turned up an article that stated that screen filters are known to cause issues like the one I was experiencing. As it turns out, I had just installed a screen filter application called Twilight. The application applies a red filter to your screen based on the time of day. The author claims this filter can help your sleep pattern when using your phone at night. Based on the suggestion in the above article, I decided to disabled Twilight. Upon doing so I was able to install applications from unknown sources again!
I must admit, this one was a stumper. Who would have thought that a screen filter application would prevent me from installing applications from unknown sources? It just goes to show that it is important to understand the changes applied to any environment because you never know what change might cause some undesirable behavior (see my previous post on comments on this blog).

© 2013, Steve Flanders. All rights reserved.