Getting an error in KPI Modeler as "{"customMessage":"failed to detect the sap language of the current session language","status":500}"

Hi Experts,

We have installed UISKPI01 in SAP NetWeaver Gateway System for Fiori Analytical Apps (KPI modeler is necessary to model the KPI) but while trying to create and Save the Group, we are Getting an error in KPI Modeler as "{"customMessage":"failed to detect the sap language of the current session language","status":500}". Similarly, when we are trying to edit the existing KPI template and assigning the Variants and Evaluations, we are facing the same error as failed to detect the sap language of the current session language","status":500.

Any idea on above error?

Thanking you,

~ Mahendra