"Unfortunately, the SystemUi has stopped" loop, cannot fix (rooted Nexus 6P 6.0.1)

[Marconis4]

I doubt this is the right forum, but I'll give it a whirl. Long story short:

-Rooted using Kingroot
-Downloaded substratum
-Installed funky/faulty system ui layer
-Phone is in endless loop of "Unfortunately the SystemUI has stopped" and it's essentially useless
-I have booted into recovery mode, cleared cache, factory reset, and it still gets the error
-I could have sworn I had TWRP, but I haven't been able to boot into it to try and delete the substratum later...am I missing a critical step, here? I used to get the TWRP screen many moons ago whenever I used to reboot, but now I'm confused. How exactly do I get there...if it's still there...

Help, because I'm on my iPhone 6 for the time being and I'm miserable. Thank you so much!

 

[ManiacJoe]

Are you sure this is not the Google update problem?
http://forums.androidcentral.com/as...x-com-android-systemui-has-stopped-error.html

 

[Marconis4]

That isn't the error I get and it happened after a susbtratum reboot.