Solution : https://service.sap.com/sap/support/notes/999639 (SAP Service marketplace login required)
Key words :
individual error messages returned, spbt_initialize function module returns, function modules th_server_list, parallel rfc processing, invalid_group_name = invalid group, internal error occurred, bc-cst component, spbt_initialize function module, parallel rfc calls, rdisp/rfc_max_wait_time reason
Related Notes :
727709 | MESSAGE_TYPE_X short dump in SPBT_INITIALIZE in RFC scenario |
74141 | Resource Management for tRFC and aRFC |