QuickSigned docs crash PDF Viewer on IOS 11

[Daniel Sidler]

Hi all,

Just wondering if anyone came across this. Users reported that a PDF could not be opened on their iPad. Investigation has shown that this particular PDF was QuickSigned on Nitro Pro and when opened on any iDevice with IOS 11, it immediately closes again. If this particular PDF is combined with a non-QuickSigned document, the reader will display the PDF ok, but then close (i.e. crash) as soon as the QuickSigned part of the PDF scrolls by.

I tried different QuickSign types: handwritten, image, drawing. They all behave the same: as soon as a QuickSignature is added, the file becomes unreadable on IOS. According to feedback I got from users, this only is a problem since IOS 11. Since I have no access to any pre-IOS 11 device, I cannot verify if this is indeed the case.

I also tried signing the same PDF with Adobe Reader DC, and not surprisingly the issue does not occur there.

Here's the setup I used to replicate the issue:

• Create PDF with Word 2016's save-as-PDF feature
• Open PDF in Nitro Pro 11.0.6.326
• QuickSign and save again
• Try to open it on an IOS 11.0.3 device
• Alternatively, use the Nitro's print-to-pdf feature out of Word. Result is the same

Now, to complicate matters, it appears that the problem only occurs with PDFs created out of Word, that contain certain document elements, namely form fields, and possibly a date selector. Not sure yet, but the problem does not occur with "plain" documents, i.e. those without fancy template stuff.

So, it looks like the PDF must be a) created with WinWord, AND b) contain Word form elements, AND c) have a QuickSignature added in Nitro Pro, AND d) opened in IOS 11. In these scenario it will crash the viewer. 

You might say that I should rather talk to Apple or MSFT. But why does it break only after adding a signature in Nitro Pro?

Dan