I've done what I was instructed to do... several times
The WebAssist extensions I have installed at the moment are: CSS Button Styler, Security Assist, Theme-It, Free Tools, CSS Form Builder, Design Extender, and eCart... in that order.
I was very careful to uninstall everything I was told to uninstall AND delete the MacFileCache.dat file before installing each program and relaunching Dreamweaver. I've downloaded all the latest versions, so that's not the issue.
If I install CSS Form Builder last, it works just fine but some of the Free Tools programs like Palette Picker stop working. If I install Free Tools last, all of those programs work just fine but I start getting error messages when I try to use CSS Form Builder.
I've tried the uninstall and reinstall routine with either CSS Form Builder of Free Tools as the last installation and I get the same results every time.