3042925 - WE21 throws MESSAGE_TYPE_X dump

When trying to access WE21 the system dumps the following:

Category                       ABAP programming error
Runtime Errors              MESSAGE_TYPE_X
ABAP Program               CL_GUI_CFW====================CP
Application Component   BC-FES-GUI
Date and Time

Short Text
 The current application has triggered a termination with a short dump.

Error analysis
 Short text of the error message:
 Control Framework : Error processing control
 Long text of the error message:

Technical information about the message:
 Message class....... CNDP
 Number................ 006

How to correct the error
 If you have access to the SAP Notes system, check there first using the following keywords:
 "MESSAGE_TYPE_X" "CL_GUI_CFW====================CP" bzw. CL_GUI_CFW====================CM002
 "FLUSH"

User and Transaction
Program...................CL_GUI_CFW====================CP
Screen.....................SAPMSEDPORT
Transaction............WE21

Information on where terminated
The termination occurred in ABAP program or include
"CL_GUI_CFW====================CP", in "FLUSH". The main program was "SAPMSEDPORT".

>>>>> MESSAGE ID 'CNDP' TYPE 'X' NUMBER 006 RAISING CNTL_ERROR.

• SAP Basis ALE
• SAP NetWeaver
• SAP Web Application Server for SAP S/4 HANA
• ABAP PLATFORM - Application Server ABAP

BASIS_ALE, EDIPOA, EDIPORT,  table buffer, report RSDBBUFF, CNDP006, duplicate entries, WE21, MESSAGE ID 'CNDP' TYPE 'X' NUMBER 006 RAISING CNTL_ERROR , KBA , BC-MID-ALE , Integration Technology ALE , BC-FES-GUI , SAP GUI for Windows , Problem