Links for Object Model Diagrams, or links that open PDF files in the ArcObjects Developer Help, return the following Microsoft Internet Explorer download error:
Internet Explorer cannot download Object Model.pdf from .
Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later.
In the ArcObjects Developer Help system, the links to Object Model Diagrams open PDF files. Because of a security fix in Microsoft Internet Explorer 5.5, links to PDF files from HTML Help .chm files no longer work.
Install the Object Model Diagrams folder.
You may still get this error message when you click the link in the Table of Contents or Index. The message should only occur once, subsequent attempts to open the PDF file should work without an error.