I have been having the hardest time linking PDF files to my Storyline course. I have followed every instruction that support said to do. Once I publish the course (from my desktop - as instructed) and before uploading it to the LMS I've been checking the compressed file to make sure the PDF files are in the project, and they are. But this error keeps popping up (attached). Can someone provide some input on why this keeps happening with just a few PDFs?