Does the NAS unit support SMB (Samba) as one of it's Network File Protocols? If not, that could be your issue. Or it could be a permissions issue on the share if it does support SMB.

Thank you for the prompt answer. I think SMB is not my NAS´s strongest side. What kind of NAS would you recommend, which is fully checked for EVA8000?

this is what MNAS4100 supports :

Network Protocol
TCP/IP, HTTP, FTP, SMB/CIFS

it is what you meaned ?

That's correct... it looks as though it supports SMB so I would check the permissions on the share and make sure you allow read for everyone. Or you could create a user on the NAS specifically for the EVA and re-add the share to the EVA with the credentials for the user you created. Example:

Create a user on NAS:

Username: eva8000
Password: eva8000
Permissions for share: Read

Now on EVA8000 add the share using the above inforamtion. The easiest way is to use the web interface. Open a web browser and enter http://IP_OF_EVA8000 in the address bar and press enter. From the Main Menu, click on "More" then "Supervisor Functions" then "Advanced Settings" and finally "Servers and Shared Folders" to get to the "Setup Network Shares" menu. From here you can add the new share.

Everything done. But how should I define the user eva8000, which is the user of the NAS on the eva ? Eva offers to me the path to the folder and hostname.

Adding Shares to the Digital Entertainer EVA8000

To add shares via the Digital Entertainer EVA8000's web interface, start a web browser (Internet Explorer 7 used in this example) and enter the IP address of the Digital Entertainer EVA8000 in the address bar. In the following picture, my Digital Entertainer EVA8000 is at IP address 192.168.1.9. To determine the IP address of your Digital Entertainer EVA8000, from the Digital Entertainer EVA8000's main menu choose "More/Supervisor Functions/System Information" and look under the Network Information (LAN) section.

From the Main Menu, click on “More” then “Supervisor Functions” then “Advanced Settings” and finally “Servers and Shared Folders” to get to the “Setup Network Shares” menu:

Enter the information to access the shares. In the screenshot above, I used the information from the user account I created, and the name of my NAS and share names.

Username: eva8000

Password: eva8000

Host: Name of NAS

Share: Name of share

Enter the info for the share you will be adding, and click the “Add network share…” button. It will appear in the list after you press the button as seen above.

Now, click on the icon that looks like a “House” on the left side to go back to the “Main Menu." From there, click on “More” then “Supervisor Functions” then click on “Full scan for media files”:

Pardizzone, You are the greatest GURU !!!!!! Thank you, everything works perfectly !!!!!!!!

Glad you got it working.... :)