What does this linker messages try to tell me?

[Frank Benoit]

Christopher Wright schrieb:
> There are two definitions for AstractObservableList.add(Object) in
> org.eclipse.core.databinding.observable.list.AstractObservableList.
> 
> Most of the rest of the problems are the same issue, just for different
> functions.
> 
> I would guess that you built one version, updated, and built again
> without first cleaning, and somehow got duplicate object files somewhere.
> 
> There are also some undefined symbols. If you haven't modified your dwt
> working copy, I'd delete it and install from scratch.

Thanks, that helped a lot.