Error messages

When opening Dreamweaver, I get the following error messages:

While executing onLoad in CSSMenuWriter.htm, the following JavaScript error(s) occurred:
In file CSSMenuWriter:
ReferenceError: onStartup is not defined

The following error message was followed by a Dreamweaver crash:

AMT Subsystem Failure
The licensing subsystem has failed catastrophically. You must reinstall or call customer support.

I am working with Dreamweaver CS3. I also have CS4 installed, but when I opened that, the site I am working is not in the list of sites to choose from.

I also have problems with the detail page, that recently began to display two error messages, when I open it. It even does that with backup copies of the detail page, that have not displayed the error messages before:

The RepeatRegion script does not define the findServerBehaviors function.

and:
The WA eCart 03ATC script does not define the findServerBehaviors function.

I put all the error messages in one thread, because I think they may be linked.