Unable to activate windows store app the app didn't start

Question

First of all I would like to say that I already tried all the solutions I could find on the internet, including Unable to Activate Windows Store App

I recently upgra

Answer 1

I have tried many solutions and nothing worked. At the end what worked for me was to change the startup project to windows phone 8.1 and after it runs OK I changed it back to windows 8.1 and it runs OK. It works for me as I am making a universal app. Hope it helps anyone else.