One thing you can try is to rename the configuration folder, which will have the effect of disabling all your extensions. Then uninstall DataAssist completely and install just DataAssist to test it. If this works, then install the rest of the extensions. If it doesn't then you can shut down Dreamweaver and Extension manager and delete the current configuration folder and rename the original one back to the original name. your extensions should be enabled again.
Here is a post that will go over how to do that: