Requests that are assigned to projects cannot switch to other clients

Hi everyone,

i activated Datasource 0FI_AR_4 in ERP DEV system client 200, when i activated the datasource i got Prompt for workbench request,

For the Field" Project", there are 2 options: Operation and daily, i select Operation

For the Field "Target", the system has automatic assigned.

then save the Transport request as XXX and activate the datasource. The datasource is also activated in Client 100.

But now the SAP Basic consultant told me that the correct Project name is "BW" in client 100.

i log in Client 100 and, use Tcode SE09, to open the Transport request XXX, and change the Project name.

However, it gives me meassage:

"Requests that are assigned to projects cannot switch to other clients"

What can i do now?

Thanks