Here is a stock ROM, MTK Backup for Opsson Opsson 6622.
With this Opsson Opsson 6622 flash file, you can flash stock ROM back to your Opsson Opsson 6622 using SP Flash Tool. This is mostly required when you have software issues with your Opsson MTK Android devices, need to revert your Opsson Opsson 6622 to factory state or unroot by flash.
Meanwhile, in most cases, flashing stock ROM on Opsson android devices corrects all software errors if you know how to do it.
Below here is the download link for the stock ROM. You may also see the tutorial page on how to flash stock ROM on Opsson and other MTK android devices below.