Recipients Unable to Open PDF,s Created in 9.0

Couple of questions:
What is the version of your PDF file (File>Properties) ?
What is the version of Acrobat/Reader being used by the recepient who cannot open the file?

I encountered a similar problem with this today using Adobe Reader 9.1.2. When attempting to open a .pdf email attachment, I was getting an Adobe Reader message that "There was an error opening this document. This file cannot be found."

The work-around solution that I found is to save the email attachment to your c-drive and then use Adobe Reader to open the document so you can read it.

- Using your email application (in my case, it is Windows Mail), select the email with the .pdf attachment and click on the Paperclip icon.
- Select Save Attachment.
- In the Save Attachments dialog box, enter the location on the c-drive where you want to save the document.
- Press the Save button.
- Now launch Adobe Reader and open the saved document using File > Open.

Yes, PDFs saved (or saved-as) by Acrobat 9 can't be opened by Reader/Acrobat 5 and older versions, since they aren't optimized using the "PDF-Optimizer" (in Acrobat 9 > Advanced menu).
This new behavior was introduced by Acrobat 9.0

Same issue can occurs with some other (old) PDF-readers.

We are unable to open any scanned documents with any version of Acrobat. It was scanned using version 8.0 Professional. We are using 9.0 Reader as well as 8.0 Professional to open and it will not open. We don't even get an error message. When you right click there are only a few options... Print, Open with Acrobat 8.0, Open With... and Send to. NONE of these options work. I have tried different versions of Adobe, different computer memory levels, different computers, even different programs to open the files...NOTHING. However, documents that were scanned just minutes earlier or later, are able to open. Any ideas?

Can you be more specific about how the documents you can not open were scanned and converted to the PDF format?

Have you tried to open the problem PDF files to see if they have a valid PDF header, "%PDF-1.#, where "#' is the version number of the PDF standard used?

They are put into an auto feeder, scanned, and then they are saved as a .pdf . They can be upto 100 page documents that are saved and then split into several different pdf's of various sizes. They are independently naming each pdf. I originally thought it was in the naming because some of the names are very long, but that is very inconsistant. Some of the longer names will open and some won't. We are unable to open certain pdf's with any programs at all, so I can't directly answer your question regarding the version numbers. Regardless....I can't open some of the documents

Signed frustrated and at a loss

I am having a similar problem - All of a sudden I am unable to open pdf files by clicking on them I have to open acrobat and then on the FILE menu use OPEN to open files. When I click on a pdf file I get "The document “xxxx.pdf” could not be opened. Acrobat cannot open files in the “Adobe PDF document” format.