Android build resetting Kindle Fire

I am running Fire OS 4.5.5, and attempting to run an Android build (minimum Android 2.3.1 (Gingerbread, API Level 9)) using Unity 4.6.8f1

When I run the apk on the Kindle Fire, it resets the device. The game has already been accepted on the Amazon Store from a previous build, but the store now indicates it is incompatible with the little red x. The game also ran fine before the latest Fire update.

Is this a problem with the older version of Unity trying to run on an updated Kindle Fire device? I cannot switch the project over to Unity 5 in a timely manner, so I'm looking for some solutions that would still work with Unity 4.6+ if possible.

Thanks in advance.