I have moved the gstreamer folder to the root of the C drive and it seems to be working.
So, I should delete the PMAutoplay file from that drive?
It might have got there when I use PM on that drive, which I sometimes do at an event and then plug it into my PC when I get back to save time rather than waiting a couple of hours transferring 8k images across from a three-day event.
Thanks for your help.
David