Problem batch with PDF file

Hi, i have a problem to create a batch from PDF file.

I need to convert a PDF create for print in a jpg for a site. I created an action that crops, adds shadows and saves in jpg format for web and it work. Now i need to use this action to create hundreds of images so i open batch and set the folder where i have all the pdf file and the action i created. I do not set any save because it is already in the action and i start the process. Photoshop opens all pdf files without doing the action and at the end i see this message "There are no source files that can be opened by photoshop"
I don't know why this process doesn't work, if i use the single action all work
Someone can help me?

Thanks a lot