Nun, nach laaangem Suchen, habe ich die Lösung endlich im englischen Forum gefunden. So funktioniert's:
Max:
The 3Dconnexion devices depend on 3Dconnexion plug-in for 3DsMax for navigation inside the application. If your [devicename] is working outside of 3DsMax , either the plug-in for 3DsMax is not installed or it does not have the proper permissions.
In the event that your version of 3DsMax was installed as administrator, you would need to add "Run as Administrator" permission to the 3Dx driver 3dxsrv.exe.
The default location of 3dxsrv.exe is C:-->Program Files-->3Dconnexion-->3Dconnexion 3DxSoftware-->3DxWare64--> 3dxsrv.exe
With 3DsMax closed, stop the driver, add the permission then re-start the driver. [Start, All Programs, 3Dconnexion, Driver, Start Driver| Stop Driver]
Right-click 3dxsrv.exe - Select Properties , then Compatibility and check only 'Run as administrator'.
The Modify /Repair function should add the 3DsMax plug-in as long as 3DsMax is closed during the process and you have the current driver installed. With the plug-in installed there is a 3DMouse news windows that opens initially when you open 3Dsmax. You should see the 3DsMax Pop-Up Menu when you press the Menu button on the SpaceMousePRO and SpacePilotPRO, the Panel button on the SpaceExplorer or the left SpaceNavigator button.
Gruß Sven