User-agent: Mozilla Thunderbird 1.0 (Windows/20041206)
But is it the final released 1.1?
If it is, then open one VE editor, and close it. Let the failure occur.
Then do Project->Clean...->Clean ALL projects. Then try it again.
The first set of errors should be impossible. I don't see how an NPE
could occur there. The second one tells me you have a bad cache, the
clean all should handle that.