Hi Dennis,
You have to provide to CMD_EI_API the partner function you want to store.
In your case, you might have not provided partner function in the input complex structure.
In clear, your report has to provide the partner functions you want to maintain.
In order to easily find which are the mandatory partner functions
for an account group, you may look at class cmd_ei_api_check, method
get_mand_partner_functions.
This method can't be used directly, but at least it will provides you
with a code sample.
I hope I could help you further.
Best regards,
Zsuzsanna