Re: I am trying to use a interactive form and it says "If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document." This is a IRS form and has worked before.

That means you are looking at the form online with a browser that uses its own (incompatible) PDF viewer, not the Adobe Reader plugin.

Either

1. download the form to your local disk and fill it from there
2. use a browser that employs the Adobe Reader plugin
3. configure your browser to use the Adobe Reader plugin: http://helpx.adobe.com/acrobat/kb/pdf-browser-plugin-configuration.html