DTPO not recognising a doc as PDF


Hope this will be an easily answered question. For one of the PDFs I’m trying to add, DTPO doesn’t seem to recognise it as a PDF, I don’t think. It states ‘pdf’ (in lower case) for kind, but the preview pane just has the PDF icon. When I open it up, it opens it in Adobe (which is the default), as opposed to opening up as a seperate window in DTPO, which is what it normally does for PDFs. Trying to convert it to Searchable does nothing.

Any ideas?

Are you able to open the PDF document with Preview.app? Maybe it’s not compatible to macOS’ PDF engine.

You’re right, I can’t open it with Preview, and yet it’s a PDF. I thought a PDF was just a PDF? Wasn’t that the point?

A PDF is not just a PDF.

Where did it come from? If it’s downloaded, can you download it again?

It’s a scan of a USAF Historical doc. The three others I downloaded from that site (afhra.af.mil/Information/Studies/) are recognised fine (including converting to Searchable), just not this one (#37 as it happens). Downloading again doesn’t seem to make any difference. Skim also opens the PDF.

Perhaps try opening it in Skim or Acrobat and then exporting it out to a new PDF?

I can’t open PDF 37 in Skim either.

Odd, now I can’t open it in Skim either. I think I’ll have to let this one go. I’m just wondering about the process and if it can be worked around in any way.

Only have Reader, not Pro

I don’t run any version of Acrobat any longer, but check for a File > Save As function.

Hmm, only gives me the option to save as an Adobe PDF file, and then when I try and do that, comes up with an error message “The document could not be saved. There was a problem reading this document (109).”

I’m curious Bluefrog, is there an especial reason you don’t use Acrobat? And is there somewhere you can point me to in regards to different ‘types’ of PDF?

The document seems to be either damaged or doesn’t comply to the PDF specification, see e.g. answers.acrobatusers.com/There- … 60898.aspx

There’s no need for it, as Apple provides Preview and DEVONthink can also display and annotate PDFs, in general.
Also, Acrobat installs browser plugins that can be problematic.

Here is a general link: prepressure.com/pdf

But it’s a larger topic than that, as you’ll note by the last paragraph and video at the bottom of the page. PDFs can be created in a variety of ways, yielding PDFs that may not conform to expected standards. You can even create PDFs in a text editor, if you’re willing to dig that hard. (I have. :smiley: )
Because of this, you should not expect a PDF “to be a PDF”, unless you generated it yourself through a known mechanism. They should generally work, but don’t expect it to always be trouble-free.

Thanks to all for your helpful and prompt comments - always much appreciated

You might want to try downloading #37 again. I downloaded it using Safari and it opened fine in Preview. I added it to DTPO and ran the OCR conversion, and it did report an error on page 272. As page 272 was a blank page of the actual scan, and page 273 was just a blank PDF page, I deleted both and ran OCR successfully.

Though I didn’t run OCR on it, I can confirm Greg’s finding about downloading the file from Safari. That one imported and displayed correctly.
I had initially downloaded it from Opera.

Just downloaded it from Opera again, and it behaves as expected.
I think it’s a one-off problem.

Still no joy actually, even when I downloaded with Safari - still can’t open in Preview, only in Adobe. Greg, would you be able to send me the doc you have OCR’d?

From my side, I’m going to put this one down to gremlins, it being it an Air Force doc and all!

I’m pretty sure I deleted the OCR document on Sunday, but I’ll put put a copy of the original, with the two problematic pages deleted, on Dropbox for a few days. * Edited to remove the link.

If this one doesn’t open in Preview, then there is something unique to your system that is creating a conflict. The first thing I would suggest to try and resolve the problem is to delete Adobe Reader.

Greg, many thanks for that, much appreciated. Had no trouble opening that one with Preview and am OCR’ing it right now.

I was also having a problem with PDF files exported from DevonAgent being read by Adobe Acrobat Reader (why the hell did install that nightmare?) Adobe is notoriously hard to exorcise and even after using CleanApp I had to do this:

shellzero.wordpress.com/2014/04 … ompletely/

and even then Lingon found two running services which I also deleted. I think it is finally gone completely but it seems I will have to redownload whatever PDF files came from DA to get them recognized by Preview which is what I want.

I will appraise if something changes.

I’m a little torn on Adobe. I realise that it’s a bit like Japanese knotweed, but on the other hand, it was the only reader capable of actually opening that PDF, and as I can’t rely on the kindness of strangers all the time, I’m loath to delete an app that meant I could at least read the PDF.