Grails Runtime Exception

[grailsX]

When i try to save one diplome instance i have a grails runtime exception, this is the trace

Error 500: Executing action [save] of controller [DiplomeController] caused exception: a different object with the same identifier value was already associated with the session: [Diplome#9]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [Diplome#9]
Servlet: grails
URI: /hremploi/grails/diplome/save.dispatch
Exception Message: a different object with the same identifier value was already associated with the session: [Diplome#9] 
Caused by: a different object with the same identifier value was already associated with the session: [Diplome#9] 
Class: DiplomeController 
At Line: [42]

41: log.debug("diplomeInstance.code = ${diplomeInstance.code} ")
42: if (diplomeInstance.save()) {
43: flash.message = "${message(code: 'default.created.message', args: [message(code: 'diplome.label', default: 'Diplome'), diplomeInstance.id])}"

 

[robmorning]

When i try to save one diplome instance i have a grails runtime exception, this is the trace

Error 500: Executing action [save] of controller [DiplomeController] caused exception: a different object with the same identifier value was already associated with the session: [Diplome#9]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [Diplome#9]
Servlet: grails
URI: /hremploi/grails/diplome/save.dispatch
Exception Message: a different object with the same identifier value was already associated with the session: [Diplome#9] 
Caused by: a different object with the same identifier value was already associated with the session: [Diplome#9] 
Class: DiplomeController 
At Line: [42]

41: log.debug("diplomeInstance.code = ${diplomeInstance.code} ")
42: if (diplomeInstance.save()) {
43: flash.message = "${message(code: 'default.created.message', args: [message(code: 'diplome.label', default: 'Diplome'), diplomeInstance.id])}"

Can you let me see how you've defined the domain class 'Diplome' ?