Adobe Reader Extended Features No Longer Available

[not applicable]

Forgive me if this topic has been covered. I searched for it but found nothing.

I was sent a PDF file created in an Adobe program. When I opened it in Adobe Reader, I could edit the forms and enter text in the text boxes, including utilizing the horizontal scroll bar when the text exceeded the size of the form window. Then, I edited and saved the file using PDF-X-Change Viewer. Now, when colleagues attempt to open the edited file in Reader (their only program) they get this message:

"The document enabled extended features in Adobe Reader. The document has been changed since it was created and use of extended features is no longer available."

So it opens in Reader, but it can't be edited, and you can't clik into the text boxes to scroll through extended text.

[Bhikkhu Pesala]

See this earlier thread.

Any PDF files I produce from PagePlus without any security restrictions can be commented on in PDF-XChange but not in Adobe Reader. Here's a comment from a Serif user on a thread about this topic where someone ran into problems with commenting on PDF files in Adobe Reader:

This is all perhaps off-topic. In the main, Adobe changed their security settings / capabilities in Reader based upon exploits and some good ol' fashion "you gotta upgrade" everyone to embed comments. Comments can contain malicious code as they are basically attachments. Attachments are really the crux of the matter. Capability for attachments was ripped out of Reader in response to security concerns and then know exploits.

When it comes down to comments and attachments specifically, such abilities in a PDF are outside Adobe's control in the sense of protecting the client-side reader. So it was removed.

Could they have handled it like Microsoft when opening DOCs or XLS files containing macros--one gets a warning and the choice to not allow them to run--instead of ripping out the ability altogether? Sure. But they didn't.

Now as mentioned, I also suspect it was in part a marketing move. One can upgrade to Acrobat Pro and do nearly anything inside a PDF.

[Bhikkhu Pesala]

Perhaps PDF-XChange should show a warning as it does for scripts.

This PDF file contains comments or attachments that might contain exploits. Do you trust the source?"

The warning could be disabled globally or remembered for PDF files from trusted domains.

I wonder if there is any realistic probability of encountering a PDF file containing an exploit in document comments?

[Paul - Tracker Supp]

Thanks for that Bhikkhu,

I also wonder at the practicality of adding such a warning. It's not something that we hear people screaming for and the devs are so busy getting V3 ready...

[BigMike]

Is it really possible to use formular input to execute any code?
I'm not familiar with the PDF specification, but if I got that right from the above postings, the problem is, that this data is saved as a kind of attachment like any other type and Adobe disabled attachments completely in its reader to prevent the execution of embedded program code. Is that correct?

PDF XChange Viewer already contains an option to enable a warning for non-pdf attachments or block them completely. Look in the "Security" section of the global preferences.

Actually I can't reproduce this with Adobe Reader 10.1.1. I've edited a formular and saved it. The text fields were still editable in Adobe Reader.

[John - Tracker Supp]

It would help us if we could get a sample of this file - prior to any changes by our viewer - so the original Adobe Version ...

and also one note - if you switch on Incremental Updates in the PDF-XChange Viewer this will preserve the Acrobat Reader extended features as they were ...

See preferences -> General - > Set Document Save Method

Thanks

[BigMike]

Since it works for me, you probably don't need the information, but:

• I used this pdf formular.
• I saved the filled pdf using "Full Save or Incremental Save for Digitally Signed"
• Opening in Adobe Reader 10.1.1 and changing formular fields worked (you get a hint, that you can't save your changes...)

Kind regards
Michael