bingo Alexis..
Explications:
The Autodesk® software no longer controls file locking by creating lock files such as DWK and DWL files as it did in earlier releases, such as AutoCAD® Release 13.
Solution:
File locking is controlled by the operating system. The operating system determines which files are opened and in use by the software.
Note: File locking cannot be turned off. The operating system performs all file locking functions.
Refer to related documents for assistance in settings for sharing files, and utilities for identifying who has a file open in a network environment.