Error & occurred when creating structure RFPOSEXT

What causes this issue?

The data dictionary structure RFPOSXEXT is automatically generated from
the structure RFPOSX and the current special fields. An error has
occurred.

System Response

RFPOSXEXT could not be modified and is no longer up-to date. A program
termination may therefore occur during reading of special fields in the
line item display.

How to fix this error?

Recreate the special fields in Customizing. If the error occurs again,
contact SAP.

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.