Same issue here. I have checked my one click settings and they seem ok, then again I'm not sure what I'm looking for. Prime Video is working but I can't install any app.
I'm based in Germany and my Amazon digital content was managed on amazon.com. After going to "Your Account > Manage your Content and Devices" on amazon.de I was given an option to transfer my digital content from amazon.com to amazon.de which I did. Then I rebooted that FireTV and this time it could install apps.
Hi I bought the Amazon fire stick in India and now I am using that in China, I have changed the location and all but still its showing me purchase failure sorry we were unable to purchase this app your account has not been charged.
I have done 1 click settings but still nothing working. Pls assist.