Amazon Apps Fail to Install on Marshmallow

[AC Question]

I use Kindle and Amazon Video daily, but since updating to marshmallow, my LG tablet and LG G4 phone versions haven't been working. My first G4 was running KitKat until it crashed and burned about 2 weeks ago, and the apps were fine, but they sent me this replacement with MM pre-installed and now none of the Amazon apps will update/install. I've tried through the Amazon mobile site and through the Underground app, but it always downloads and then fails at installation. I've tried updating Kindle through the play store and get the error -505 code each time. The Amazon store doesn't give me a specific error code. I've enabled install from unknown sources and I've tried enabling Audible again, but it still isn't working. Any suggestions??

 

[B. Diddy]

Welcome to Android Central! Try going to Settings>Apps>All, ​select Download Manager, and Clear Cache/Clear Data. Now try again.