BAdI /SAPSLL/CUS_PRO_DET has not been implemented

What causes this issue?

Stock separation by customs status is active for this transaction. BAdI
<DS:SIMG./SAPSLL/CUS_PRO_DET>/SAPSLL/CUS_PRO_DET</> provides the
following methods,
<DS:IO./SAPSLL/IF_EX_CUS_PRO_DET BND_WHSE_STOCK_POST_REL_MM>BND_WHSE
_STOCK_POST_REL_MM</> and
<DS:IO./SAPSLL/IF_EX_CUS_PRO_DET BND_WHSE_STOCK_POST_REL_SD>BND_WHSE
_STOCK_POST_REL_SD</>,
which the system uses to determine whether the transaction is relevant
for GTS inventory management. These methods have not been implemented.

System Response

The transaction cannot be processed further.

How to fix this error?

Implement the above methods in BAdI
<DS:SIMG./SAPSLL/CUS_PRO_DET>/SAPSLL/CUS_PRO_DET</>.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.