Comment 1 for bug 1220277

This issue was caused by the fix for #1214350, in which Alex copy&pasted the amazon app back into lp:webapps-applicatons, so that it could be default-installed (although in hindsight I'm wondering if maybe there wasn't a better way to do that...).

For now the best course of action is probably to just stop installing unity-webapps-amazon package.