One or more XREF chunks were not found

[ketter]

I have a sneaky suspicion that this has nothing to do with PDF-XChange Editor, but since your support is so much better than the other software developers that I am dealing with, I thought I would see if you could point me in the right direction. I have a file that I first open in PDF-XChange Editor on Windows 7 Pro 64-bit. It is fine at that point. I then open it on my iPad using PDF Expert (by Readdle) through a WebDAV connection. I mark it up on the tablet and sync it back. Then I open it agin in PDF-XChange Editor on Windows 7 Pro 64-bit and I get an error: "One or more XREF chunks were not found". Again my guess is that PDF Expert is messing up the file, but I want to verify. I have attached a small sample file that went through this process. Can you verify that there is something actually wrong with the file? And if there is, can you tell me what to pass onto the Readdle tech support so I can get this fixed? Thanks!

[Will - Tracker Supp]

Hi Ketter,

Thanks for the post and sample! The document is damaged an needs to be repaired. This can be done by resaving the document.

Can you advise on what seems to have caused the damaged? e.g. what were you doing before it occurred and, out of curiosity, is there a specific reason that leads you to believe it's not something that the Editor has done? I ask because it's extremely hard to tell whether or not the Editor may be the cause of the issue, without all relevant information. There are many, many potential reasons why a document could become damaged: even just leaving a document stored on a hard drive, for a very long time, can sometimes result in a loss of information (though that shouldn't be an issue with good hard drives).

Cheers,

[ketter]

Will,

Just to verify, I ran through the process again.
* from PDF-XChange Editor, select File, New Document, with blank pages.
* use typewriter function to place text on it.
* save it and open it multiple times - no problems or errors (testA.pdf)
* open it on my iPad using PDF Expert via WebDAV connection
* markup the file using PDF Expert
* email it to myself (testB.pdf)
* email it to myself with comments flattened (testB-flattened.pdf)
* sync it back to the folder via WebDAV connection (testC.pdf)
testB, testB-flattened, and testC all report errors when opened in PDF-XChange Editor. testB and testC also do not include the markup that I did in PDF Expert. I think this PDF Expert app is messing up the file. I just wanted to confirm that it wasn't a bad error on your Editor's part. And if it is a true error, I was hoping you could share some info that I could pass to Readdle tech support so they take this seriously and fix it. Thanks. I have zipped and attached the four test files I mentioned above.

[Will - Tracker Supp]

Hi ketter,

From what I can tell, the issue is with PDF Expert and they are not correctly making additional entries to the XREF table. I would suggest that you send them this:

hp_xref_issue_explanation.pdf

(10.35 KiB) Downloaded 147 times

This document was drawn up for a different user's issue with another software manufacturer, but I believe that it may still be worth sending to the makers of PDF Expert. Other than that, I'm afraid that there's really little more that we can do.

Cheers,

[ketter]

Thanks Will!
I just needed confirmation. I will take follow up with this other company. I wish their tech support was as good as yours...or that you made a version of PDF XChange Editor for iOS!
Ken

[Will - Tracker Supp]

Hi Ken,

No worries! We certainly do our best

or that you made a version of PDF XChange Editor for iOS!

Discussions around this are set to take place, be no guarantees are being made yet. It would require that we completely re-write the Editor from the ground-up, so no matter what happens, it would still be a long way off.

Cheers,

[ketter]

Thanks Will!

[Will - Tracker Supp]

[Lzcat - Tracker Supp]

Hi Ken.
Actually this document has other issue - incorrect incremental update.
Problem is with incorrect /Index [1 1 9 1 14 6] value in trailer (file contain one more object, which is already described in object stream, but does not listed in /Index entry).
Corrected file is attached.
HTH.

[ketter]

I didn't see Victor's post until just now. Thanks for that information. I was wondering if one of you could help me out just a little further. I have a file that was synced to my server by one of the Readdle PDF Expert tech support people as a test. I'm not trying to start a finger-pointing war, I'm just trying to resolve this issue. The tech support person who synced this file to me said if I opened it with an Adobe product it would display and that I can't see the annotations because I am using your Editor. I tested and I can see the annotations with Adobe Reader and when I open it with XChange Editor, it says problems were detected with the document and the annotations do not display. I'm attaching the file, can you please take a look at it? Does Adobe Reader ignore the errors or automatically correct them? Why does Reader display this file when Editor says it has issues? If there is a specific problem with this file, I will pass the information back to Readdle PDF Expert tech support and see if I can get this fixed. Thanks again for all your help!

[Will - Tracker Supp]

Hi ketter,

Thanks for info. - I believe that Adobe silently corrects issues, with no warning. After some complaints from users, we may well do the same. If you re-save the document, does everything display correctly?

Cheers,

[Lzcat - Tracker Supp]

Hi Ken.
Issue is completely same as in previous file - incorrect /Index entry in trailer.
And yes, Adobe almost never report about errors in file, but silently correct them.
HTH.

[ketter]

Save As removes the error, but it also removes the markups. So it appears that Adobe is saying, "this is wrong, we will correct it" and Tracker is saying, "this is wrong, we will remove it".

Regardless, I need to try to explain to Readdle what is wrong with their software. And I'd like to make an enhancement request to you. If it is possible, it would be great if XChange Editor would repair bad PDFs rather than removing the information. Thanks again for the help. I will now go see if Readdle will work with me on this.

Ken

[Lzcat - Tracker Supp]

Hi Ken.
We also try to repair broken files, but not in all cases we can get same results as Adobe - sometimes we do better, sometimes - Adobe. We do not remove information, we just try to recover as much as possible, and in this case recovery is working a bit worse as in Adobe. But at least we notifying that file has problem, instead of Adobe products.
And yes, if you know how to repair files like or even better than Adobe does - we will be happy improve our code.

[ketter]

My comments weren't meant to slight PDF-XChange Editor or your programmers. I'm not a programmer (the little I do in PHP doesn't count) and I don't know the inner workings of the PDF format. I've always been very pleased with your products and I think Tracker is very responsive to user requests. So I hope I didn't come across negatively. I'm just trying to resolve this issue as quickly as I can for my users. Thanks again for your help.

Ken

[Will - Tracker Supp]

Hi Ken,

Thanks for the info. - That's a little different, if we're removing content where Adobe isn't. I've made a ticket for that (RT-3484), so the Dev. Team will look into whether there is something that we can do to fix that.

Regarding what happened to break the file in the first place, this happens for the reason that Victor stated previously:

...incorrect incremental update.
Problem is with incorrect /Index [1 1 9 1 14 6] value in trailer (file contains one more object, which is already described in object stream, but is not listed in /Index entry).

I'd suggest advising them on this, and the fact that Adobe simply corrects the file silently. The issue with the file almost certainly starts with something that they have done, the issue in our software is we do not appear to optimally fix the file.

Cheers,

[ketter]

Thanks Will, I appreciate it! I already sent them the original file as created by them, the corrected file (that I think Victor provided), and the information you just quoted. I'm hoping they will be as responsive as Tracker is and that they will provide a fix. We will see.

Regards,
Ken

[Will - Tracker Supp]

No worries Ken! Good luck

P.S. I forgot to mention that fixing damaged documents, silently, has been discussed recently and I believe that it's the route we're going to go down in the future, though I can't say when.

Cheers,

[ketter]

Will,

I just double-checked. Using that "small test copy.pdf" file which I have already uploaded. If I open it in Adobe Reader, it displays some markups. If I open it in PDF-XChange Editor, they do not display and it reports a problems with the file. If I then Save As to a new PDF file and then re-open it in PDF-XChange Editor, the errors are gone, but so are the markups. And if I open this saved copy in Adobe Reader, they are still gone. So it is definitely removing markup information. But I'm hoping Readdle will fix their iOS app so it doesn't cause the error in the first place.

Thanks,
Ken

[Lzcat - Tracker Supp]

Hi Ken.
Again, we do not remove information from pdf, we just cannot recover it. And when you press Save button we saving everything that we can recover, nothing more. So if we did not recover your markups it is our failure, but if you want to save document in this state - do not blame us, it was your choice, isn't it? And yes, real problem is that file is broken (using software you know) and at the moment we cannot recover it properly. What to do in this satiation is your choice, but stop pressing us - we are aware about problem and will fix it in one of the future builds.

[ketter]

Victor,

I'm sorry. I did not mean to sound like I was pressing Tracker. I understand completely that this is the fault of the other company that makes the iOS app we are using. And I obviously made a wrong choice of words: I should have said recover not remove. I have no complaints about Tracker. You all make great software and we appreciate the great response we get from tech support. That is why we keep renewing the maintenance agreement.

If you add the ability to recover the file, that will be greatly appreciated. But I am going to keep after the other software company in hopes that they will fix the bug in their software. Thanks for the explanations.

Regards,
Ken

[Will - Tracker Supp]

Hi Ken,

Not a problem at all. Victor's choice of words may have been a little harsh - while the issue was not initially with us, we are not recovering information that should be recoverable and I agree that this should be fixed. Whether information is being removed, or simply not recovered, is not immediately clear and I have to say that it wasn't a distinction that I had personally made either.

We'll make sure that this is improved as soon as we can, but obviously it is always best if the issue is fixed at the source (i.e. the iOS app breaking the document).

Cheers,

[ketter]

By the way, forgot to mention...I like the new website design. And I just saw the announcement that the new Editor Plus will include a forms designer. Great news! Thanks.

[Will - Tracker Supp]