Hobbywing 120A V2.1 software

[Hog]

Recently acquired one of the above to go in a 2wd I built, but the previous owner has installed V3 Stock software on it, and I want to revert it to V2 930MOD software.

No matter what I (and a few others) have tried, we can't get it back to the V2 version. There also seems to be a conflict between the ESC and program box where I get an error message telling me to upgrade the software (I guess that's correct if the ESC is V3 and program box V2). I've tried this and now the program box won't talk to my other ESC's! I've tried installing various software versions onto the box but seem to be going nowhere.

Is it case that once a HW ESC is upgraded to V3 it can't go back to V2? Or am I just being dumb and not following the correct procedure? I just want to lose the STK setting with too many turbo and boost variables and run it the same as the other couple of HW ESC's I own on the 930MOD software.

Can anyone help please?