playframework use find with IN and a list of models

i've got a problem with the following code, written in play (1.2.4):

List<MSprache> sprachen = MSprache.find("active = ?", true).fetch();
 List<MFieldDscr> textey     = MFieldDscr.find("sprache IN", sprachen).fetch();
 

And if i execute a test, wich test this part of code, the following Error displays:

A java.lang.IllegalArgumentException has been caught, org.hibernate.hql.ast.QuerySyntaxException: unexpected token: null near line 1, column 48 [from models.Sprache.MFieldDscr where sprache IN]
 

I don't understand where the misstake is... Can anybody help me?
Greetz
V

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