Converting reference doc numbers from 35 to 16 digits is not possible

What causes this issue?

It is not possible for function module REF_DOC_NO_CONVERSION_RANGE to
transfer reference document numbers with more than 16 digits to fields
that have only 16 digits.
Longer reference numbers can only be used in systems with enhanced
domain XBLNR1 which is only intended for Public Sector client Federal
Government.

System Response

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

How to fix this error?

Check whether the request of the system called with a reference number
of more than 16 digits is correct.
If it is correct, you must also convert the system called to the
extended reference document number.
If it is not correct, you must change the request accordingly.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.