all of those extensions have been updated to newer versions.
Uninstall all 4, then download the newer versions and install in this order:
eCart 5.0.7
Free Tools 1.0.5
Design Extender 1.1.5
Data Bridge 1.1.4
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.