How to reproduce:

• Add a connection to an external ECM
• In The ECM, delete a folder
• Click on the folder in the documents' hierarchy
• An error occurs because the folder does not exist anymore => OK
• Click on OK, the error occurs several times => KO
• Refresh the document's hierarchy
• The deleted folder still appears => KO

Same behavior with the external ECM's root when the ECM is off => KO