The problem is the path which exceeds what is allowed by the OP; look to this and count how many characters(letters): c:\xxx \6.02 Paint - Products and Applications; Protective Coatings; Pipeline Coatings \6.02 Paint - Products and Applications; Protective Coatings; Pipeline Coatings
then add to that the file name.pdf.
The solution is simple, Marty can kindly save the pdf files in a folder named 6.02 and compress it to 6.02; this way the path becomes much shorter and would be readable by Windows applications.

Best wishes