If you are using Firefox and are getting this error : “Cannot use Adobe Reader to view PDF in your web browser. Reader will now exit. Please exit your browser and try again.”
One solution is to double check the pdf file association inside your browser.
1. Open Firefox
2. Go to the ‘Tools’ menu
3. Select ‘Optionis’
4. Choose the ‘Applications’ tab
5. Find the ‘Adobe Acrobat Document’ and change the action to use ‘Adobe Acrobat’ or ‘Adobe Reader xx’