Error loading a project in MODELER

Hi Expert;

Yesterday, I created a process MODELER version 6.5.1 that I saved normally.
Today, I wanted to open the project, impossible to open it, here is the message and the details of the message that MODELER displays.

Erreur Message :
An error occurred trying load “SAProcess/SAP_Reservation”

Details message :
com.wm.bpm.persist.PersistException: Inheritance marker not found for level 0 at com.wm.bpm.persist.RepoPersistentSession$RepoReader.readIDataObject(Unknown Source) at com.wm.bpm.persist.RepoPersistentSession$RepoReader.readObject(Unknown Source) at com.wm.bpm.persist.RepoPersistentSession._rawLoad(Unknown Source) at com.wm.bpm.persist.RepoPersistentSession.load(Unknown Source) at com.wm.bpm.designer.BPMPlugin$OpenRecentAction$ Source) at java.awt.event.InvocationEvent.dispatch( at java.awt.EventQueue.dispatchEvent( at java.awt.EventDispatchThread.pumpOneEventForHierarchy( at java.awt.EventDispatchThread.pumpEventsForHierarchy( at java.awt.EventDispatchThread.pumpEvents( at java.awt.EventDispatchThread.pumpEvents( at

Please can you help me on this topic, as this is very urgent.

Thanks in advance for your help