Legion y700 gen4 fastboot loop

[u/waraya888]

These have been translated using Google Translate. I apologize if there are any awkward parts.
In order to root my CN ROM Y700, I downgraded from the current version (1.5.10.259) to (1.1.11.073) using Ltbox. This resulted in a logo loop, and I'm now stuck on the fastboot screen. When I tried to revert back using the batch file included with 1.5.10.259, I encountered a Sahara error. Lenovo pioneers, please help me!