Internal error when implementing extension (see long text)

What causes this issue?

An internal error occurred during the implementation of a
customer-specific enhancement. An API module was called with an initial
object reference (parameter <NP>IO_OBJECT</>).
The API modules are function
modules and begin with <NP>API_RE_</>.

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?

Within the BAdI implementation, transfer the parameter <NP>IO_OBJECT</>
from the BAdI method directly to the API module.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.