What version of form builder?
Is it form Builder 2?
If it is Form Builder 2, you will need to uninstall Universal Email and HTML Editor. The functionality of these two extension is integrated into Form Builder 2.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.