It would be easier for us to help you if you posted a small project showing the problem.
klaus,
I created another project and selected the "XUI Views" library, and no errors.
From the original errors Log:
Current declaration does not match previous one.<br />Previous: {Type=ColorPicker,Rank=0, RemoteObject=False}<br />Current: {Type=ColorPickerPart,Rank=0, RemoteObject=True}
It's interesting that this line is referencing the "ColorPicker", which I have an Activity named that.
So it may have something to do with this Activity.
I'll check it out some more.