Solution: For the Best Experience, Open this PDF Portfolio in Acrobat X

Symptoms: When viewing a PDF on a website with an embedded viewer, the PDF displays the message "For the Best Experience, Open this PDF Portfolio in Acrobat X or Adobe Reader X or Later".

Cause: This can happen when the uploaded adobe document is saved as a PDF portfolio. This is common when combining PDF files or saving emails as PDFs using the Adobe Plug In.
PDF portfolios only display their cover document in web embedded PDF viewers. The get Adobe Reader Now! screen is the default portfolio cover sheet.

Solution: To ensure your document can be read by web embedded PDF viewers make sure it is saved as a standard PDF document and not a portfolio.

For PDF Files combined in Adobe Acrobat Pro.

From the combine PDF tool window, selection the options button.
From the Options Menu ensure "Save as PDF Portfolio" is not checked.
Click Ok.
Combine your PDF Files and save your new combined document.

For PDFs created from Emails using the Adobe Plug in

In Outlook choose the acrobat add in menu
On the Acrobat add in menu choose change conversion settings.
Uncheck output portfolio.
Now PDFs saved using the Adobe Acrobat Plug in will save and standard PDFS and not Portfolios.