Error adding custom field bseg OXk3

Hi Gurus.

I have added a new field to the bseg through the OXK3 transaction code.

I did it with the expert mode and aparently everything worked sucessfull  because at last step when i execute it it just gave me a warnig message

The field appears at bseg and at the transactions codes FB50..

the problem is that when i try to fullfill it at transaction code FB50 it doesnt  alow me to record anything.

I went once again to the OXK3 transaction code and when i press the botón of field information it shows me a red line with the next message:

BB137 : E : Field not contained in active versión of BSEG.

Have you got any idea of how can i solve this??

Thanks in advance!!!