Hi Peter,
It's based on a Finder Selection. I select two or more images, right-click the mouse, and select "Convert to PDF" from the Services menu. It works perfectly when done this way.
When I open KM and assign a hotkey macro to run the Workflow, using Execute an Automator Workflow, a PDF is generated, but it's blank. The Finder selection is not used. The Automator Workflow I use in the macro is from the services menu. I've also tried using the exact same workflow placed elsewhere on the HDD. Same result. For some reason, the workflow is not run properly when invoked through KM.
The images are JPGs.
Thank you.