HTTP request failed - internal server error in Approve Purchase Orders app
We have configured the standard Approve Purchase Orders app in our central hub deployment Fiori landscape. We have activated the corresponding OData service GBAPP_POAPPROVAL with the system alias of the back-end ERP system in the front-end server. Also we have assigned the roles SAP_MM_TCR_T_X1 and SAP_MM_BCR_BUYER_X1 in front-end server and SAP_MM_PO_APV_APP in the back-end ERP system. The user also has the copy of the role SAP_UI2_USER_700 assigned with the authorizations added for INTEROP and PAGE_BUILDER_PERS services.
Our test user also has the S_RFCACL role assigned in the back-end system. Also we have configured the workflow task ID of the PO approval workflow at the corresponding path in SPRO in the back-end system.
Now when we login to the Fiori Launchpad with the test user, we see the Approve Purchase Orders tile with "Error" instead of the work-item count. Below are the errors that we see in developer condole of Google Chrome:
Also the error logs from the transaction /IWFND/ERROR_LOG are as shown below:
Can anyone please help us out in determining why this issue might be occurring?