Some users using older versions of Internet Explorer (IE 8 and older) have reported issues with attaching their résumé or cover letter to their job application.
Certain conditions on your computer, such as security settings or browser cookies, can prevent you from viewing and converting files to a PDF. Often, the fastest solution is to try to open the page using a different browser. Try any of the following browsers that you have not already tried:
Switching web browsers to Google Chrome, or Firefox recommended in these cases. They are great, free alternatives, which handle this file upload process much smoother.
Alternatively, you can always try the editor option to copy/paste your résumé in to complete your application.
For more help and troubleshooting on Internet Explorer, try Adobe's support page: Problem with the browser or its settings.