Default has stopped - Error

Hello Friends! Going mad with this error. Hope someone helps me!!

I have been flashing various zips and was downloading various apps, When I rebooted, It shows me it is upgrading and then this error occurs showing

" has stopped" It goes on popping up!

I have tried the below steps!

1. Reseted The Phone!
2. Restored To Stock by following this thread and using the bat filel -

Bootloader is unlocked and I am still facing the error!

Hope someone helps me!! Will be waiting eagerly for your answers!