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$OpenRecentAction$OpenerRunnable.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178) at java.awt.EventQueue.dispatchEvent(EventQueue.java:454) at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137) at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

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

Thanks in advance for your help