Adobe Acrobat Standard DC - Strange Square Characters When Combining Multiple PDF Documents

[Rob22550193y1gc]

Hi,

Some of the business users have started to report an issue when combining individual PDF documents.  When these PDF documents are opened individually the files render correctly, however when you combine around 6+ indifidual PDF documents it then displays the results below and the strange square characters.  This is extremely time consuming as the only work around to date is to save each individual PDF using Nova PDF and then combine

These are all PDF files which have been created by the users and sent externally to a client to stamp and then they are return to the original user to combine into one single PDF document pack.

I have tested creating local PDF documents with random numbers and letters and the issue does not occur.

FURTHER INFORMATION

1) EACH individual PDF file appears fine (both on the screen and when printed). There are NO unprintable characters within the PDF.
2) CAN combine approx 5 PDF files. All Fonts & characters appear fine (within the combined PDF). WILL also print OK. NO unprintable characters.
3) Now try to combine 6+ PDF files into ONE PDF file (NOT good). The COMBINED PDF will display on the SCREEN unprintable characters (€ = square box) on nearly every page!
Occurs RANDOMLY throughout many of the pages.
4) Fonts are Arial & Times New Roman, Calibri, Century Gothic.
5) REMEMBER: EVERY individual PDF will appear OK & Print OK.
SMALL numbers of combined PDF's will appear OK & Print OK.
ONLY when many PDF's are combined does this problem appear!!
6) Happens to multiple people in our office environment. All running Windows 10 (with latest patches), and Acrobat Acrobat DC
7) This is NOT a printer problem!!!!
You can see all the square boxes on the SCREEN when viewing the "combined" PDF files.
8) Plenty of system memory. Plenty of Hard drive space.

Appreciate any help on this

Thanks
Rob

[Amal.]

Hi Rob

Hope you are doing well and sorry too hear that.

Is this a behavior with a particular set of PDF files? Please try with different set of PDFs and try to combine and check if its working fine.

What is the version of the Acrobat std DC you are using? To check the version go to help > About Acrobat and make sure you have the recent version installed. Go to help > Check for updates and reboot the computer once.

You may also try to repair the installation from the help menu (Windows only)

Also, try to create the PDF portfolio of ththese files as described here https://helpx.adobe.com/acrobat/using/create-customize-pdf-portfolios.html and see if that works for you.

Regards

Amal

[Rob22550193y1gc]

Hi Amal,

Thanks for responding, this is happening on different PDFs, reported by approx 7 users that I am aware of.

The version is 2021.007.20099

They are all working within a Citrix environment

I will review the portfolio option and see if this helps

Rgds

Rob

[neiderhl]

I have the same issue.  It's sporadic though.. Same PDF document for 2x shipments created.  1st set of documents combined without issue.  Second set will not combine without changing characters to boxes!  I've checked the preferences to ensure all fonts embedded & "Save as Optimizes for Fast Web View" is UNchecked, but still the issue persists randomly. 

[Luke Jennings3]

You can check your pdf for properly embedded fonts by going to File> Properties> Fonts. All listed fonts should say embedded or embedded subset. Your issue may be caused by improperly created pdfs, suggested fixes are included in this discussion and the links to related discussions.

[Abambo]

Also: check the applications creating the PDF file. It may give you a hint on what application creates bad PDF files.

[Luke Jennings3]

Here is a link to a similar issue which may help:

https://community.adobe.com/t5/acrobat-discussions/creating-a-pdf-with-multiple-files-results-in-cor...

[Rob22550193y1gc]

Thanks Luke,

Indeed this does appear to be a very similar issue, our user are using Acrobat Standard DC version 2021.007.20099 in a Citrix environment.

If I read this article correctly it seems there is no simple solution here and a workaround is all the user can do for now until a permanent solution is identified.

Apprecaite your response

Rgds

Rob

[Luke Jennings3]

I suspect one or more of your returned PDFs has improperly embedded fonts, if this is the case, I suggest using an Acrobat preflight fixup to try to embed the fonts before combining them, this is more of a fix than a work-around. Ideally, your stamped pdfs should arrive with correctly embedded fonts. If the pdfs you send out have properly embedded fonts (as indicated by the document properties, not because they look and print ok), then it's possible someone is inadvertently unembedding a font, or otherwise damaging the PDF when applying a stamp. You may see improvement by trying any number of preflight fixups on the individual returned pdfs (see attached screen shot), or possibly saving as PDF/X-1a, which sometimes fixes small issues.  (this will also flatten any transparency)

Some things that can damage a pdf: Opening it in Apple Preview, optimizing it to reduce the size and unembed fonts, saving it from a non-Adobe application.

If one of the above suggestions helps, you can create an Acrobat Action to quickly apply it to a pdf or folder of pdfs.

[Rob22550193y1gc]

Thanks for taking the time to respond Luke.  I will check out your suggestions

Rgds

Rob

[Rob22550193y1gc]

Hi Luke,

Update on this issue:

We have deployed Adobe Acrobat Pro DC to one of the impacted users machines. Version 2021.011.20039

I have checked the original PDF document created internally and some of the fonts do not show embedded when checking File>Properties>Fonts (I am unsure why this is the case when it has been created internally and converted from a word document)

We repeated the issue by inserting individual PDF documents using the Organise Pages feature and upon inserting the 6th individual PDF page the document corrupted and displayed the strange characters (per the image on my original report above)

I then tried the PreFlight Fixup option per your screen shot, it does report back an issue with embedded fonts, however it is not clear to me how to fix this.  I tried saving as a PDF-X but this changed the document slightly by spacing out the strange square characters.

The only workaround still is to print each individual PDF to NOVA pdf and embedding the newly created PDF file.  Obviously quite time consuming as there are mutliple colleague performing this action on a daily basis.

Many thanks for your assistance.

Rgds

Rob

[Luke Jennings3]

Sorry for the delayed response.

The fact that some of your internally created pdfs are showing non-embedded fonts is important, this is the likely cause of your font issue on the combined pdf. There are several ways to create a pdf from Word. Search Google for "Word to PDF" to find the best method for your conditions. You can almost always produce a pdf with properly embedded fonts from Word if the settings and method are correct, once the correct procedure is followed, your combined pdfs should be good. 

The Embed missing fonts preflight often fixes the unembedded fonts on a pdf, select the preflight and click on the Analyze and fix button at the bottom right corner of the window, re-check the font embedding after running the preflight. Run this preflight on the individual pdfs, before combining them.