[AC Question]

A couple of days ago my phone developed an issue where it stated that com.android.systemui has stopped unexpectedly, initially this went after pressing 'ok' a couple of times but now it's just stuck in a loop and reappears every time I press ok. I've looked online and followed the recommendations of clearing the partition cache and booting in safe mode, i've even done a factory reset but this still hasn't cured it. Does anyone know where I go from here? the phone is now unusable with the constant prompt, I only got it in September and have no idea what has caused the fault. I'd like to just install fresh firmware on it via my laptop but not sure how/if this is possible. The phone is on EE if that makes a difference.

Thanks