I have customized a SharePoint 2010 master page, all is working except dialog boxes are displaying empty. For example, if I try to add users to a group the dialog comes up, but no content is in the box.
What could be the issue ?
use the developer tools and see if there is your custom css is blanking the form up. As you may know that you can remove css rules from the developer tool on the spot without changing the master page itself to see the effect (just to save you any hassle)