Issue description

When I try to edit Distribution Chain for a given product by clicking edit icon:

This is the data I input in Distribution Chain edit page:

When I click Back button to try to save the change, I meet with error message "Specify at least one number for the business partner".

I am a little bit confused since in Distribution Chain edit page, there seems not to have any field which can allow me to specify a business partner.

How to find the root cause of this error message

Hover the mouse on message area to get technical information. Message type: E, message id: R11, message number: 123.

Now I have to set a break point on a given method which is executed before this error message is raised. I choose to set break point on method CL_BSP_WD_VIEW_MANAGER~PROCESS_NAV_QUEUE. After this break point is triggered,  set a dynamic break point via context menu below:

After that click F8, then debugger automatically stops at the very line where the specified error message is raised. From the callstack I know that this error occurs when WebUI framework tries to retrieve the data of set type CRMM_PR_SALESA:

The root cause of this issue is: Inside settype FM call, the loc_bupa is initial.

After I maintain a partner in Delivering Location field, the error is gone.