random black images when capturing with Canon 60D - by: martingo

While capturing an image sequence using the latest Kstars with the latest INDI library i get random black images in the sequence . I'm using the following:
Kstars Version 2.9.8
INDI Library 1.7.5
Raspberry 3B+ with latest updates and upgrades
Canon 60D with the Canon INDI driver

I have done several fresh installs to troubleshoot the problem. It keeps happening every time.
Any advice?

Thanks
Martin G