3436256 - The error CMD_API 100 or VMD_API 100 occurs during the synchronization

In BP transaction, while updating customer details in already created FLCU01 customer, you are receiving the following error when you try to save the bp:

Customer-specific date were not saved due to error CMD_API100 (see long text!)

Message no. CVI_BDT_ADAPTER051

customer &: mandatory partner role & is missing

CMD_API 100

Or in BP transaction, while updating vendor details in already created FLVN01 vendor, you are receiving the following error when you try to save the bp:

Supplier-specific date were not saved due to error VMD_API100 (see long text!)

Message no. CVI_BDT_ADAPTER051

vendor &: mandatory partner role & is missing

VMD_API 100

Additionally, there could be short dump ASSERTION_FAILED raised in Class CVI_EI_VENDOR_FUNCTIONS when maintaining master data using the API CL_MD_BP_MAINTAIN.

• SAP S/4HANA
• SAP ERP

KNVP, KNVV, LFM1, WYT3, CMD_API 100, VMD_API 100 , KBA , LO-MD-BP-SYN , Synchronization Business Partner with Customer/Vendor , CA-FS-CVI , Customer Vendor Integration – FS-BP part , Problem