[NTG-context] \setupnotation[footnote][numberconversion=numerals] in latest beta

Dear list, I have the following sample that I cannot compile with latest beta: \setupnotation[footnote][numberconversion=numerals] \starttext Text\footnote{Text.}. \stoptext numberconversion=numerals seems to be the problematic part. Has this option been changed or is it a bug? Many thanks for your help, Pablo -- http://www.ousia.tk