I am unable to print pdf documents on my Image Class d880 printer. I used to be able to...but am not able to anymore. Any reason why this is happening?

Why Won't My Canon Printer Print PDF Files
Follow this method to rectify this problem:
Step 1: Open the PDF file in Adobe Acrobat Reader Step 2: Check the print option on the toolbar afterward.
Step 3: Now press the Advanced option and then pick the Print as Image choice. Then press Ok and Print and see the printable PDF files.
Step 4: The PDF file is recreated. Choose a way to re-create the file and re-download it and save it to the hard disk.
Step 5: Check if the PDF files are working and you're getting the prints.

Hi, do you mean you can't print all the files in pdf or you can't print certain pdf files? If you can print certain pdf files, it is probably that the pdf is protected by owner password which prevents you from copying, editing and printing pdf files. You need to remove pdf password using a pdf password remover like AnyBizSoft.