3562546 - Gateway client shows HTTP Open failed: HTTP Internal Error

Testing OData requests in the Gateway Client transaction (/n/IWFND/GW_CLIENT) after kernel upgrade is not possible, due to Information pop-up:

HTTP Open failed: HTTP Internal Error 

or

HTTP Send failed: 
HTTPIO_PLG_BAD_HANDLE-Fehlermeldung beim Senden der Daten.

Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental. 

SAP Gateway (OData)

SAP Gateway, SAP OData Gateway, OData Gateway, Gateway Client, Kernel update, Kernel upgrade, SAP S/4HANA, ODATA operations, error, HTTP Open failed, HTTP Send failed, HTTP Internal Error, icm trace, ABAP platform, Administration Tools, Update Work Processes, HTTPIO_PLG_BAD_HANDLE, Fehlermeldung beim Senden der Daten, /IWFND/GW_CLIENT , KBA , OPU-GW-COR , Framework , BC-CST-IC , Internet Communication Manager , OPU-BSE-SDE , SAP Data Enablement , BC-MID-RFC , RFC , Problem