UMI Diamond receives all updates automatically via FOTA method. You need this tool only in case of emergency (if you've bricked your phone), if you want to apply a clean install or if you want to clear all root access and custom recovery to make your phone able to receive FOTA updates again.
Resources for SPFT:
ROM: UMiDiamond_20161208-194714_songlixin_PC.rar - Extract the .rar file before use. The scatter file (MT6755_Android_scatter.txt) is inside the extracted folder, together with the other elements
Here's an optional solution to start the flashing process on your UMI Diamond if the standard method doesn't work. It's especially useful if your phone is bricked or is stuck in bootloop
1. Connect your UMI Diamond to USB.
2. Start the flashing process with the Download button in the flasher app.
3. Press and keep pressed the power button of your phone until the flashing process starts (red bar appears at the bottom of the app window), then release it. In this process you have to keep the power button pressed for about 10 seconds.
4. Wait until the flashing process finishes.
Manual (local) OTA update method instructions
1. Copy the downloaded .zip file to either the internal memory or the SD card of your phone
2. Go to Settings --> About phone --> Wireless update
3. Tap the 3-dot menu button at the top right corner and select Local updates
4. Brows for the ...update.zip file and select it
5. Tap Install now, comfirm the process with OK and wait until the process will be finished
Update file for manual OTA update: UMi_Diamond_V7.0_20161208_update.zip