Lenovo Vibe Z2 Pro (K920) stuck on boot up screen?

So there was a system update. I downloaded it and installed it. It installed and everything but when I tried to turn it on it showed the Lenovo logo and "Powered by Android", that disappears and then the Lenovo boot up intro starts playing. Now that intro is the problem. It freezes halfway trough. Sometimes later sometimes sooner.
I tried everything. I launched into recovery mode and factory reset it, ereased user data and wiped fuse data (or what it's called).
The phone is rooted but I have not had any problems with it as to now.