Download Umi RootJoy v1.0.4 from here or here. Download previous version from here.
Archive name: Umi Super MTK6755 Android 6.0 Smartphone Firmware 206153 160706
Archive size: 9.61 MB
Archive content: ROOTJOY_126.96.36.19916_Setup.exe
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.