Probleme Webdav

Hi all
 
I have a big problem with Webdav.
I can't access to the webdav URL
http://localhost:8080/jahia/webdav/shared, I have an error : " XXXX is
not accessible".
 
If I look on the http request error, that indicate to me that because a
folder doesn't exist any more.
If I want to create again the folder with jahia, I have also an error.
 
I think this folder was badly deleted.
 
Is anybody has an idea to fix this problem?
 
I have another problem but not with webdav.
Sometime when I want add a file in a container, I don't know why but
Jahia create a folder with the same name. Is anyone has the same problem
and an Idea to fix the problem?
 
Thanks again for your help.
 
Nicolas