Error when generating an auxiliary program

What causes this issue?

An internal report is generated to create the explain plan. An error
occurred when ths internal report was generated.

System Response

The system continues.

How to fix this error?

Try to display the explain plan for another matchcode ID. If this is
possible, try to repeat your original action.
If this error occurs again, please contact the SAP hotline.

Error message extract from SAP system. Copyright SAP SE.