I definitely have the 8.0.2 update installed.
The thing that's confusing me is that this has just started happening out of the blue.
I've not tried to upgrade Validation Toolkit to a newer version, because I was aware that you no longer support DW8 so any new versions released might be problematic.
Nor have I upgraded DW or Windows for that matter.
When you say to rename the configuration folder, do you mean the folder that's within the Dreamweaver 8 folder "Application Data\Macromedia\Dreamweaver 8\Configuration"?
It's ok to just completely rename this without affecting, for example, other extensions?
Appreciate the advice, thank you.