Corrupted system partition, incompatible mod. Solution: Boot into recovery (Vol Up+Power) → Wipe cache partition → Factory reset. If that fails, reflash the complete firmware.
You can manage the firmware for your through official online updates or by downloading offline packages directly from ZTE. How to Update Firmware Firmware ZTE Axon 50 Lite
There are two primary methods for managing firmware on your Axon 50 Lite: 1. Official OTA Update (Recommended) Corrupted system partition, incompatible mod