one customer reported that system sent the above message when they chose the option "Release for billing" . Product was correctly created and Service Order/Service Confirmation didn't display any problem
However, the error log shown "Reference Object Header Data Error: Material xxx has not been maintained" as soon as they set "Release for billing" option.
I would like to share with you the root cause of this message :
product was not created any description in the language of Sold to Party. The logic tries to read the material text first in the language of the SP. If it's not found, it tries to read it in the language of the Sales Organization if it differs.