Honestly, I don't know without comparing the preloader from the flashable version to the OTA version. I thought there's only two preloader versions for Android 6 and Android 7 as a complete Android 6 TWRP backup doesn't work on a Android 7 preloader, you get a nice black screen, download didn't work so I had to do a format and download. What's strange is, I've never had that error, and I can't find any info on it. I think it could be the drivers.
Uninstall and remove the current mediatek preloader usb vcom driver and any remnants in device manager. In device manager(right click This PC or My computer), show hidden devices and remove and uninstall all mediatek devices under ports and install the newest drivers;
Windows 7, http://drivers.softpedia.com/get/MOBILE ... ws-7.shtml
Windows 10, http://drivers.softpedia.com/get/MOBILE ... s-10.shtml
When flashing phone off, select scatter file, select download on menu, press download button, connect phone.