It's something to do with my 'proper' PC as I can get it to work on my notebook. I am on Win10 so that could be it.
May be no good anyway as, apparently, since I've updated to the latest firmware there is no way to revert to older firmware where the gimbal calibration can be loaded in.
The drone flies OK but has a continual message saying the gimbal is not calibrated ..even though I have calibrated it and it works fine!!