Solution : https://service.sap.com/sap/support/notes/40584 (SAP Service marketplace login required)
Key words : 
additional key words crt, add-ons add-ons, profile parameter rdisp/bufrefmode, 1g execute program rsspam03, buffer synchronization takes place, sap buffer synchronization mechanism, syntactically incorrect customer program, sap buffer synchronization, option program -> generate, entering command /$sync
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