remove themedreamer
In my case, removing the ThemeDreamer extension fixed this problem.
I don't remember this error before their latest update, and I've used both Sculptor and Themedreamer, so it may be just this latest version of ThemeDreamer.
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.