Have you ever had trouble reading a PDF file on an iOS device such as an iPad? A PDF file that was emailed to me wouldn’t open on iPhone or iPad, and not even the file name showed up correctly. The file opened normally on my computer, so I knew the PDF file wasn’t completely corrupted. While it’s still a mystery why the PDF file didn’t work on iOS, in the end I did fix the problem. Here’s how.

I didn’t have access to the original document, so I couldn’t export the PDF file again from the source. I had to try and fix it on my side. I started by opening it in Adobe Acrobat X Pro, where I tried choosing File > Save As > PDF to write out a new copy of the file. After that didn’t work, I tried Reduced Size PDF on the same submenu. That didn’t work either. It didn’t help to open the PDF file in Apple Preview and choose File > Save As.

At this point I was stumped. Knowing that the file worked fine on a computer, I was still convinced that there had to be a way to fix it.

I next used Acrobat Pro X to save it to PDF-X/1A, a standard for high-end prepress. This time it failed even to convert, which turned out to be a good thing because the failure showed me an error message. The message suggested that I run the PDF through the Preflight feature using the Convert to sRGB preflight profile. That was a great idea; I should have thought of using Preflight sooner since the purpose of a preflight feature is to catch file problems before they cost time and money later down the line.

In Acrobat X Pro, Preflight is buried in the Print Production panel in the Tools pane on the right side of the Acrobat workspace. I selected Convert to sRGB, and then clicked the Analyze and Fix button.

That worked! The next time I transferred the PDF file to iPad, it was perfectly readable.

In the end, my troubleshooting guess was correct: Find something that can rewrite the PDF file radically enough to change whatever was causing the error, even without knowing the exact problem.

Of course, not everyone has Acrobat Pro and it is not cheap, but if you have access to some versions of Adobe Creative Suite, Acrobat Pro is included and so you have it. Keep Acrobat Pro in mind if you run into problems like this one. [Edit: As of 2013 Adobe Creative Suite is now Adobe Creative Cloud.]

While Apple Preview on a Mac doesn’t have the variety of production tools available in Acrobat Pro, there is another way to do something similar: Open ColorSync Utility, choose File > Open and open the PDF file, and then choose Create Generic PDFX-3 from the Filter pop-up menu at the bottom of the document window. I did not try that in my case, though, since I had already fixed mine.

What might have caused the problem? I may never know for sure, but based on what fixed it, I’d guess that there was a problem with at least one of the color images in the PDF file. It looked like it had been created in Word with maps pasted from Windows screen shots. Maybe there were indexed-color BMP or GIF images in it. While that should not have been a problem, what we do know is that the Convert to sRGB preflight profile did fix the problem.

While this solution solved my problem, it may not fix every problem with reading PDF files on iOS devices. If it doesn’t solve your issue, I hope that describing a successful troubleshooting process helps point you in the right direction. Good luck!