PROBLEMS: Old PDF files...

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MP3746
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Re: PROBLEMS: Old PDF files...

Post by MP3746 » Tue Jan 28 2020 10:02am

First of all, we need to understand the symptoms. What errors are being reported and is there an error code? If Adobe Reader cannot open a PDF file, then the file is not in the correct format.

A PDF file must adhere to specific formats with a block of bytes (called a header) that specifies identifies the file as a PDF file followed by a version. This is also followed by a body (consisting of text, images and other visual objects), a database for cross referencing and a footer. If each of these sections of a PDF file are missing or do not contain the necessary signature, it is NOT a PDF file or the file has been corrupted with incorrect data.

If it is feasible for you to upload one of the invalid files into cloud storage with a link for me to download, I can analayse with a hex editor and maybe attempt a fix.
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Re: PROBLEMS: Old PDF files...

Post by expressman33 » Tue Jan 28 2020 11:01am

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Re: PROBLEMS: Old PDF files...

Post by BeautifulSunshine » Tue Jan 28 2020 12:36pm

MP3746 wrote:
Tue Jan 28 2020 10:02am
First of all, we need to understand the symptoms. What errors are being reported and is there an error code? If Adobe Reader cannot open a PDF file, then the file is not in the correct format.

A PDF file must adhere to specific formats with a block of bytes (called a header) that specifies identifies the file as a PDF file followed by a version. This is also followed by a body (consisting of text, images and other visual objects), a database for cross referencing and a footer. If each of these sections of a PDF file are missing or do not contain the necessary signature, it is NOT a PDF file or the file has been corrupted with incorrect data.

If it is feasible for you to upload one of the invalid files into cloud storage with a link for me to download, I can analayse with a hex editor and maybe attempt a fix.
A very generous offer.
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Re: PROBLEMS: Old PDF files...

Post by Boro Boy » Tue Jan 28 2020 1:23pm

AAAlphaThunder wrote:
Tue Jan 28 2020 12:36pm
MP3746 wrote:
Tue Jan 28 2020 10:02am
First of all, we need to understand the symptoms. What errors are being reported and is there an error code? If Adobe Reader cannot open a PDF file, then the file is not in the correct format.

A PDF file must adhere to specific formats with a block of bytes (called a header) that specifies identifies the file as a PDF file followed by a version. This is also followed by a body (consisting of text, images and other visual objects), a database for cross referencing and a footer. If each of these sections of a PDF file are missing or do not contain the necessary signature, it is NOT a PDF file or the file has been corrupted with incorrect data.

If it is feasible for you to upload one of the invalid files into cloud storage with a link for me to download, I can analayse with a hex editor and maybe attempt a fix.
A very generous offer.
Thank you for the offer but I don't want to start transferring files.

As far as the visuals are concerned there is no error code, it just comes up black when any pdf file is attempted to be loaded.

I just really wanted to know if other members were experiencing the same issues following the recent Adobe update...?

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Re: PROBLEMS: Old PDF files...

Post by BeautifulSunshine » Tue Jan 28 2020 4:08pm

Boro Boy wrote:
Tue Jan 28 2020 1:23pm
AAAlphaThunder wrote:
Tue Jan 28 2020 12:36pm
MP3746 wrote:
Tue Jan 28 2020 10:02am
First of all, we need to understand the symptoms. What errors are being reported and is there an error code? If Adobe Reader cannot open a PDF file, then the file is not in the correct format.

A PDF file must adhere to specific formats with a block of bytes (called a header) that specifies identifies the file as a PDF file followed by a version. This is also followed by a body (consisting of text, images and other visual objects), a database for cross referencing and a footer. If each of these sections of a PDF file are missing or do not contain the necessary signature, it is NOT a PDF file or the file has been corrupted with incorrect data.

If it is feasible for you to upload one of the invalid files into cloud storage with a link for me to download, I can analayse with a hex editor and maybe attempt a fix.
A very generous offer.
Thank you for the offer but I don't want to start transferring files.

As far as the visuals are concerned there is no error code, it just comes up black when any pdf file is attempted to be loaded.

I just really wanted to know if other members were experiencing the same issues following the recent Adobe update...?
Fine for me.
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Re: PROBLEMS: Old PDF files...

Post by Boro Boy » Tue Jan 28 2020 10:53pm

This is only an issue for accessing older pdf. files since the recent Adobe update.

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Re: PROBLEMS: Old PDF files...

Post by jaytee » Wed Jan 29 2020 2:56am

If the issue is as a result of an Adobe update, then try a different PDF Reader - others are available:

10 Best PDF Readers for Windows 10, 8.1, 7 (2019)

Adobe Acrobat Reader DC
SumatraPDF
Your Web Browser
Nitro Reader
Foxit reader
Google Drive
Slim PDF
Expert PDF Reader
Javelin PDF Reader
PDF-XChange Editor

10 Best Free PDF Reader Software For Windows [2019 Edition]

fossbytes.com/best-free-pdf-reader-windows/
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MP3746
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Re: PROBLEMS: Old PDF files...

Post by MP3746 » Wed Jan 29 2020 9:34am

Boro Boy wrote:
Tue Jan 28 2020 1:23pm
AAAlphaThunder wrote:
Tue Jan 28 2020 12:36pm
MP3746 wrote:
Tue Jan 28 2020 10:02am
First of all, we need to understand the symptoms. What errors are being reported and is there an error code? If Adobe Reader cannot open a PDF file, then the file is not in the correct format.

A PDF file must adhere to specific formats with a block of bytes (called a header) that specifies identifies the file as a PDF file followed by a version. This is also followed by a body (consisting of text, images and other visual objects), a database for cross referencing and a footer. If each of these sections of a PDF file are missing or do not contain the necessary signature, it is NOT a PDF file or the file has been corrupted with incorrect data.

If it is feasible for you to upload one of the invalid files into cloud storage with a link for me to download, I can analayse with a hex editor and maybe attempt a fix.
A very generous offer.
Thank you for the offer but I don't want to start transferring files.

As far as the visuals are concerned there is no error code, it just comes up black when any pdf file is attempted to be loaded.

I just really wanted to know if other members were experiencing the same issues following the recent Adobe update...?

Now you mention that you only see black pages in the document, that does suggest that the PDF files are valid. It also suggests that Adobe Reader is blanking out the entire document for security reasons. I had a read of the url that ExpressMan posted and that is worth reading because there is information pertaining to Protected Mode, which may be the cause of the black pages in the document.

There is also the possibility that earlier PDF files had security issues and Adobe Reader works around these issues by blanking out the whole document. People with knowledge of the internal structure of PDFs can embed an executable file within the document and launch the executable file when the document is opened. With that in mind, it may not be so wise to send me the documents to me for examination!

The most recent Windows 10 Pro and Enterprise editions provide sandboxing features, so make use of them when experimenting with your PDF files, otherwise use a Virtual Machine.
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Re: PROBLEMS: Old PDF files...

Post by Boro Boy » Wed Jan 29 2020 9:37am

jaytee wrote:
Wed Jan 29 2020 2:56am
If the issue is as a result of an Adobe update, then try a different PDF Reader - others are available:

10 Best PDF Readers for Windows 10, 8.1, 7 (2019)

Adobe Acrobat Reader DC
SumatraPDF
Your Web Browser
Nitro Reader
Foxit reader
Google Drive
Slim PDF
Expert PDF Reader
Javelin PDF Reader
PDF-XChange Editor

10 Best Free PDF Reader Software For Windows [2019 Edition]

fossbytes.com/best-free-pdf-reader-windows/
Good advice, thank you.

I am so surprised that no other member seems to be suffering the same issues. For web security purposes I always down-load the latest updates and patches but it doesn't seem to have done me any good this time. Remember this issue is only affecting access to older stored pdf. files...

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Re: PROBLEMS: Old PDF files...

Post by pabenny » Wed Jan 29 2020 10:50am

Why are you surprised? I would be astonished if such universal software as Acrobat reader (and for that matter Office) was not backwards compatible.

It very much sounds like the problem is your end. If the files are old, it's seems unlikely there are security issues not identified by versions of Acrobat reader between then and now. Most likely is that your files have become corrupted.

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