Thanks Jason! It helped a lot. Dreamweaver works now. But it seems to have been something wrong with certain XTensions.
I have now reinstalled all the extensions (Data Bridge 1.2.1, Free Tools 1.1.2, Design Extender 1.2.0 and 5.0.7 ECART).
Now, when I select 'WebAssist -> Database -> Computer Assist Pages - I get an error message.
This reads: "When OnLoad run in WADA_Main.htm occurred following JavaScript error: file 'WADA_Main': initializeUI not defined." (see attached screenshot).
Another error, which also comes up is: "When the find was run in connection WADYN_CONN.htm occurred a JavaScript error" please note that this is translated.
Could the problem be that I have reinstalled the extension in the wrong order?