I also use Windows Phone 8.1 GDR1 developer preview
The startup still crashed

I'm Currently use Nokia Lumia 520,
And i'm beta tester of Opera Mini

1. At start-up this app force closed then i start to uninstall then install it again
2. Lucky, i can use Opera Mini
3. This app is good, but accidentally....
4. When i open facebook.com for the first time it was good
5. Then, then i started open a new tab, success
6. In a few minutes, i opened facebook.com again
7. It start force closed again when the loading bar full

Please fix this problem