I have been searching how to downgrade VR600 v2.0 firmware
Finally i learnt a solution. I know lots of people has same problem that's why i want to share it with you.
1- Download beta firmware from http://support.tp-link.com/f/a9365b0cc4/?dl=1
2- Download firmware which you want to downgrade.
3- Turn off wi-fi adapter.
4- Unplug dsl cable or phone line (whichever you use..)
5- Make a connection to modem by cable
6- Update firmware with a file you downloaded first ( http://support.tp-link.com/f/a9365b0cc4/?dl=1 ) i loaded twice because first time it didn't load properly. After loading properly it returns to sing in page.
7- Now you can load a firmware whatever you want.
I had NL version by this program, i have returned to 2020 version. For other users i tried to downgrade 2017 version, it worked. i perefer to use 2020 version.
Please after finishing downgrade, let me know.