Solution : https://service.sap.com/sap/support/notes/400748 (SAP Service marketplace login required)
Key words : 
additional key words ehs27bsp01psesprh_error-not_found-classesprh_error-not_found-numberc1f2_substances_read, specification managementthe read api, specification information system, attached correction instruction, sets error message, error message, specification management, symptom component, product safetymodule, assignment header
Related Notes : 
       
| 870612 | Incorrect warning message "no values" when you copy recipes | 
| 839195 | Identification of non-valuated properties with the BAPI | 
| 391318 | EH&S 2.7B corrections: Support Package 01 |