Thanks for the advice - I hadn't realised these extensions were not compatible with CS6 (and I've just looked and couldn't find anything on the website to say this; it's not in the general info section nor in the downloads page or links). It's surpising as they were installed and I had no errors at all under DW CS6, *until* Free Tools was added.
In practical terms, though - the upgrades are listed in my 'upgrade page' as way more than I can pay - $500 to return me to functionality I had before isn't going to happen, unless you are suggesting the Sales might offer a better price given the circumstances.
I appreciate the suggestion for recreating the users configuration folder, but the link supplied does not cover this at all - not that I can find. And why do I need to recreate it if I'm trying to eradicate all WebAssist extensions and suchlike, so that I can start again? Surely this will retain code that is redundant, until or unless I reinstall some of the extensions.
Advice is much appreciated.