with eCart 5, you should install eCart first, then free tools, design extender and data bridge.
make sure you are getting the most recent versions of the extensions.
if you still have errors, then recreating the configuration folder would be best.
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.