Custom Language Z1 in Readonly UME
we have implemented a portal with a readonly ABAP-System datasource.
In the ABAP backend we have a customized language "z1".
If a user has configured this custom language z1 in backend, the locale in the portal is null.
in the ume administration the user has an empty language field.
we have already add the language into the portal localelisteservice but it seems that the portal dont know the language z1yet
with all other languages it works fine... do we have to configure the dataSourceConfiguration_abap.xml ?