Why was my App update disabled for Amazon Apps?

[AC Question]

App update disabled for Amazon Apps

When I try to update an app from Amazon Apps, it downloads and shows me the Install screen, but the Install button is disabled.

 

[B. Diddy]

Re: App update disabled for Amazon Apps

Welcome to Android Central! Do you have any screen dimming apps installed, like Lux? These apps can strangely disable the Install button. Deactivate any screen dimming, or uninstall the dimming app, then try Amazon Appstore again.