The Short Version

Your .pdfp files are just bundles containing the contents as a single PDF file and some metadata, so it doesn’t matter that PDF Clerk Pro no longer runs on current versions of MacOS.

The Details

I depend on PDFs to run my business: expense receipts, sending proposals to clients, contracts, and so on. I rely on tools that slice and dice PDFs, perform OCR, make annotations easy… on MacOS I used to use PDFClerk — so much so that I bought the Pro version. I used it for years, especially to wrangle expense receipts into expense reports. Eventually, I discovered PDFPen, which I now use every day, and which I love. (If you buy PDFPen, please tell them that I said “Hi!” It’s one of a handful of tools that I happily upgrade.) I left PDFClerk behind (sorry!) and, while I wasn’t looking, PDFClerk faded into the background. I preferred PDFPen in part because it didn’t use a specialized file format for its contents, but rather operated directly on PDFs.

Fast forward to today, when I rudely discovered that MacOS 10.12 (Sierra) can’t open PDFClerk Pro 3.12. If you haven’t opened PDFClerk in a while, then I suggest trying it now, especially if you’re still on an older version of MacOS 10. I had a moment of panic. What will I do?! Who has MacOS 10.6 lying around on an old backup drive or something?

No worry. The .pdfp file is just a package that wraps its contents as a single PDF file and adds a metadata file (main.clerkdata) and a QuickLook file. In Finder, right-click the .pdfp package, choose Show Package Contents, and you’ll find the .pdf file, which you can rescue. You’ll lose the PDFClerk metadata, but I don’t even remember what was in there, so I don’t mind losing that metadata.

So if you used PDFClerk, there’s no need to fear no longer being able to use it: rescue the PDFs inside your .pdfp files, use PDFPen, and all is well again. Enjoy.