5.6.0.16 unable to open UltraVNC sessions.

Hi RDM team,

i have updated from RDM 5.6.0.15 to 5.6.0.16 and it's not longer possible to open an UltraVNC session.
error:

ArgumentNullException - Value cannot be null.
Parameter name: path1

at System.IO.Path.Combine(String path1, String path2)
at Devolutions.RemoteDesktopManager.Managers.InstallationPathManager.CheckFileNameIsValid(String aBasePath, InstallationPathInfo aInstallationPathInfo)
at Devolutions.RemoteDesktopManager.Managers.InstallationPathManager.EnsureConfigured(String aName)
at Devolutions.RemoteDesktopManager.Managers.VNCManager.EnsureConfigured(VNCType aVNCType)
at Devolutions.RemoteDesktopManager.Business.Connectors.VNCConnector.Connect(Connection aConnection, OpenConnectionMode aOpenConnectionMode)
at Devolutions.RemoteDesktopManager.Managers.ConnectionManager.OpenConnection(Connection aConnection, OpenConnectionMode aOpenConnectionMode)
at Devolutions.RemoteDesktopManager.Forms.FrmMain.OpenConnection(Connection[] aCurrentConnections)
at Devolutions.RemoteDesktopManager.Frames.ConnectionViews.FreConnectionTreeView.tvList_NodeMouseDoubleClick(Object sender, TreeNodeMouseClickEventArgs e)
at System.Windows.Forms.TreeView.OnNodeMouseDoubleClick(TreeNodeMouseClickEventArgs e)
at System.Windows.Forms.TreeView.WndProc(Message& m)
at Devolutions.Private.Controls.TreeViewXP.WndProc(Message& message)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

After that i have exchanged the RemoteDesktopManager.exe back to 5.6.0.15 and an UltraVNC session starts up again.
Can you please check the 5.6.0.16 in this case again?

many thanks Bob