Windows phone 8 app working on emulator but crashing on device?

Question

Here I am again, begging for help.

I just submitted my very first app on the Windows phone Store, for Windows Phone 8 and 8.1.

The app was working exactly the way I wanted to when compiling from visual studio to the emulator. Now that it's published, I asked a friend to download it and test it for me (as I don't have a WP8, sadly), and the app is unusable.

Here is the problem : By using the app normally, it writes some data in xml files, and then the user is able to read these files (formatted to look like normal text and not xml, no worries). But everytime the user reach a point where the xml files are needed, the app stop working without any message, just going back to WP main menu.

The XML files are located in my project folder (MyApp/Saves/file.xml)

The question is : Why this is working on emulator but not on devices ?

Should I declare these files somewhere like in the app manifest ? Or just reading/writing xml files can't work in the app folder, and then I should use Local Storage ? I hope I'm explaining it well..

Thanks in advance !

Answer 1

As I found the answer, here I am talking to myself.

The answer is : It is impossible to modify any XML file contained in the app folder directly. The only solution is to use IsolatedStorage, which i'll not explain here, there's plenty of well explained tutorials about it everywhere on the web.

Thanks to the ones who answered.