Hi Oxa
Yes, the previous version was running. I just wanted to draw your attention to the process for the update from within the previous version:
start previous version
message appears notifying of new version and would you like to update now
answer yes and follow on screen instructions
the above error is generated
manually close previous version running in the background
installation proceeds OK
i.e. the installation process does not automatically close the previous version, nor does it tell you to do so. This could be frustrating and confusing.
Of course if I download the installation file and run it without Market Feeder Pro running, all is in order.