Alpha2 Metadata Error on Start

[Tom Zeller]

>>Based on the last entry of the stack trace, I can imagine that one of
>>my attribute encoder definitions is bad, but the original error
>>message was misleading by mentioning metadata. Anyway, I believe I
>>have a lead on tracking down the root problem.
>
> That is utterly bizarre.

Just chatting : a different error is thrown if a bean is defined in an
XML config file which is lacking a required ID, so my guess is this
has to do with the attribute mapper reading from metadata as part of
the encoders. Just a guess.