[news.eclipse.technology.epf] "Object not contained in a resource" Excep

[quentin.deme@xxxxxx (Quentin DEME)]

Hello,

I've made an EPF Composer plug-in allowing to instanciate a project from a 
model defined with EPF.

In the plug-in, the user can make changes about things existing in the 
specified model.

The instanciation needs to load a resource, and remove some tasks and 
milestones from it. I use TaskDescriptorImpl.delete(), and there's no 
problem, until I use resource.save(map).

resource.save(map) gives the following exception :

Exception save() : 
org.eclipse.emf.ecore.resource.Resource$IOWrappedException: The object 
'org.eclipse.epf.uma.impl.MilestoneImpl@174aee5 (name: ) (guid: , 
briefDescription: , suppressed: false, orderingGuide: ) (presentationName: 
, shapeicon: null, nodeicon: null) (prefix: , isPlanned: true, 
hasMultipleOccurrences: false, isOptional: false) (isRepeatable: false, 
isOngoing: false, isEventDriven: false)' is not contained in a resource.

In this case, it's the removal of a milestone that provokes this error.

I've searched the Internet, and I found that this exception means that an 
object A contains a reference to the removed object B.

I tried other functions like 
TaskDescriptorImpl.removeFromAllOppositeFeatures(), or 
setSuppressed(true), in addition to delete().
I also tried to cast into TaskDescriptor and do setSuppressed(true) and 
delete()... It doesn't solve the problem.

This is the very last problem that occurs in my project, and I really need 
your help. The modifications that the user makes are not correctly done, 
and some modifications are not performed, because of this exception.

Thanks in advance,

Quentin Demé