This might be of some use for those who have installed the update and are now stuck in a bootloop.
I recently installed a zip from ZTE's website which had a bad md5. This put me into a bootloop and I think the reason was due to downloading it from a WiFi connection. There was literally nothing that I could do to get back to factory settings as it wiped recovery and any form of reset. The only thing that was available was FTM..Even still I only reset the phone by fastboot and that's it.
OK, so I contacted ZTE directly and told them what had happened. These phones are relatively new and if you are still in the 1 year warranty period guess what....you can get your phone replaced for free. I think that most people forget about this. You MUST call ZTE directly and have ALL of your information about the phone available. ZTE will take care of the problem.
I had to do this after trying to fix my phone myself, but failed. They will check the phone and make sure that nothing had been tampered with, and that there is no water damage.
Just FYI... I DID have my phone rooted and heavily modified. Even though I restored a stock rom and made sure that EVWRYTHING was stock and all root traces were removed this can still happen. It's just a bad download that you will never know about until you try and flash.
Even after all that, I was a little worried that I didn't remove all traces of root. After they looked over the phone I got a status update that said the new phone was on its way. BRILLIANT!!!
I am not sure that it was all worth it though. I no longer can take 360 photo's anymore and the camera seems to be sorely lacking since this update. Not to mention the phone seems to keep a very long log of "previously running apps" and even though I close them all down, I can immediately check back and see a ton of other apps that I closed 10 minutes ago. Very strange.
So, I have a little question for all of you who bought this phone early on....do you have a gyro in your phone, or just accelerometer? Just curious why all of these 360 cameras don't work now that they replaced my phone lol.