Hi,
I have two different feedimporters.
One for productid and image and one for productid and title.
When I run the one for productid and title I got this logmessage:

Unable to generate the derived image located at public://styles/..

What does this mean? Does it mean the image is already there and it can't be made again?
Why does my feedimporter which does nothing with image "touch" the image field as such that this message is triggered?

Thanks a lot in advance for your reply!
I have feeds, commerce_feeds, feeds xpath parser running in latest versions.

Greetings,
Martijn