Error 505 when installing Facebook Messenger
My girlfriend and I both Sony Xperia Z5 Compact have the same problem (Error 505) after we had updatet to Android 7 Nougat. I think for the most people the problem will become public, when the old facebook app gets outdatet and force an update. I was so stupid to deinstall facebook, messanger and sitemanager for a fresh install try and now are only able to use these facebook platforms by browser. I postet the same problem in Sony Support Forum and are also shocked, that such popular app errors on android 7 results only in 1-3 problem topics at this time.

Official answer from sony: Make a factory reset because problem happens with update... not the espacted answer - but seems the only solution, when the company don't want to fix these issue.