Default method called for object type "&1"

trados = docu -> bc -> bcsrvgbt

What causes this issue?

The system did not find a display function for object type &V1& that was
specially written for the DRB.

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

System Response

The system assumes that &V1& is a business object type (BOR object type)
and
tries to call up the default method for this object type. This is
usually a display method.

Error message extract from SAP system. Copyright SAP SE.