The folder does exist, but the permissions on the /enterprise folder do not allow you to browse there. This is because of a google requirement of folders in the root of the file system. You can get to the folder in the file browser by going to /enterprise, then tapping just to the right of where it says "/enterprise" near the top of the screen. Type in /usr so that it now says /enteprise/usr and press the checkmark on the keyboard. You can now see the contents of that folder.
Thanks, for you help. Unfortunatelly i can not test it now because i do not have the device :-)
I´ll comunictae this with customer.
Is it the same with taken pictures? On the device they are visible in the DCIM folder on the SD, but from the PC browser not. Is it also some security feature from Android?