Hallo,
prüfe doch einmal nach, ob dein Netserver User disabled ist

User Profiles Disabled for iSeries NetServer

iSeries NetServer limits the number of sign on attempts based on the system value QMAXSIGN. When accessing iSeries NetServer, the Windows Networking Client will make repeated attempts to log on (under the covers) if the authorization fails. This can disable the user profile for iSeries NetServer access only. Therefore, it is recommended that QMAXSIGN be set to 5 or higher. A user profile can be disabled for iSeries NetServer use while other functions (such as emulation session sign-on) are not affected. Also, if the profile is displayed it will still be Enabled.

On R510 and above, disabled iSeries NetServer profiles can be viewed and enabled from iSeries Navigator. Open iSeries Navigator, expand My Connections, expand the iSeries connection, expand Network, expand Servers, and select TCP/IP. In the list of TCP servers, right-click on iSeries NetServer and select Disabled User Profiles. Enable the profile if it has been disabled.

When a user profile is disabled for iSeries NetServer, QSYSOPR message queue will log message CPIB682 - User profile xxxxxxxx disabled for iSeries Support for Windows Network Neighborhood access. Running the CHGUSRPRF command on the disabled user profile (no additional parameters are required) or restarting the iSeries NetServer will enable it.

Notes: 1 Changes to the system value QMAXSIGN do not take effect for iSeries NetServer users until the server is started again. It is also recommended that the QMAXSIGN system value not be set to *NOMAX.
2 V5R1 has added support to reduce the frequency of profiles being disabled for IBM AS/400 NetServer™ use due to multiple login attempts by Windows under the covers. Refer to Rochester Support Center document number 23103226 , R510 AS/400 NetServer and Disabled User Profiles , for further information. To link to knowledgebase document 23103226 immediately, click here .
3 Any action that updates the last access date on the user profile will cause the iSeries NetServer profile to be re-enabled if it has become disabled.