PDFpen and PDFpenPro 8.0.1
Smile has issued version 8.0.1 of PDFpen and PDFpenPro, the first maintenance release after the recent upgrade (see “PDFpen 8 Adds Attachments, Digital Signatures, and More,” 28 April 2016). The PDF editing apps now enable you to press Shift-Space to scroll up a page, improve signature field compatibility with Adobe products, fix a crash that was caused by displaying the choice widget, and make improvements to picking up old license codes for free update checking.
Upgrades for single-user licenses of PDFpen and PDFpenPro each cost $30 (those who purchased either PDFpen 7 or PDFpenPro 7 after 1 January 2016 are eligible for free upgrades). Both PDFpen and PDFpenPro are now available from the Mac App Store, but you can get version 8 of either edition from Smile and receive upgrade pricing. Just download the latest version of the app from the Smile Web site and launch it: the registration process recognizes the Mac App Store versions and applies the appropriate upgrade price. ($74.95/$124.95 new with a 20 percent discount
for TidBITS members, $30 upgrade, free update from version 8.0, 70.3/70.9 MB, release notes, 10.10+)
Everytime I try to open a particular pdf (it is a 20-page academic article that opens fine in PDF Expert and Preview, PDFpenRpo 8.0.1 stalls out and must be force quit. Since I just bought the product (thinking it might be a step up from PDF Expert) I am very disappointed. Gees.
It's entirely possible the PDF is corrupted in a way that only PDFpenPro will notice (Preview doesn't know what to do with a lot of things that can be done in PDF).
Send the file to Smile's support - I can guarantee they'll be very interested in looking at what's happening with it.