Unable to access certain functions after upgrade to 11.1

Hello,

I've just upgraded our DVLS server to 3.1 and after that upgraded my RDMS Enterprise to 11.1.
After that I am unable to create new sessions and it does not recognize the fact that I am an administrator nor any of the security groups I belong to.

Logging in from an older client (10.5.4.0) works fine and I can access all the data and create new sessions.

The error message I get when I try to create a new session is as follows:

System.Security.Cryptography.CryptographicException: Padding is invalid and cannot be removed.
at System.Security.Cryptography.RijndaelManagedTransform.DecryptData(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount, Byte[]& outputBuffer, Int32 outputOffset, PaddingMode paddingMode, Boolean fLast)
at System.Security.Cryptography.RijndaelManagedTransform.TransformFinalBlock(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount)
at System.Security.Cryptography.CryptoStream.FlushFinalBlock()
at System.Security.Cryptography.CryptoStream.Dispose(Boolean disposing)
at System.IO.Stream.Close()
at System.IO.Stream.Dispose()
at A.caffdb7cd64b8f25021522cf428831983.cbe3acd6492484a5bc671e384b09ae0f8(String c976455d4fb74ab6075c2618c33425db6, String c30234935d04135eee043de8bc49f7858, String cc775c49dcea664820c922a35fdf0bfb6)
at Devolutions.RemoteDesktopManager.Business.DataSources.PersonalXmlConnectionDataSource.LoadData()
at Devolutions.RemoteDesktopManager.Business.DataSources.PersonalXmlConnectionDataSource.GetConnections()
at A.c7e2cef3f825a7ec6ad4bada24eb65d62.caf5606902cd4b8fa72d75fe22722f906()
at A.c7e2cef3f825a7ec6ad4bada24eb65d62.get_c96fb366f86ad2bded84356bc5f76bce6()
at A.c7e2cef3f825a7ec6ad4bada24eb65d62.get_cd51ecb38581233121f4ec2311e63e3a9()
at Devolutions.RemoteDesktopManager.Forms.FrmConnection.LoadConnectionInControls(Connection connectionToLoad)
at Devolutions.RemoteDesktopManager.Forms.FrmConnection.cd010602130da8ffa095e72f712cf3d19(Object c19f185fd70cefc696ba148af1c4faf54, EventArgs cf1018bb83ec7debd818319fd3cb4844e)
at System.Windows.Forms.Form.OnLoad(EventArgs e)
at Devolutions.RemoteDesktopManager.Forms.FrmBase.OnLoad(EventArgs e)
at System.Windows.Forms.Form.OnCreateControl()
at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
at System.Windows.Forms.Control.CreateControl()
at System.Windows.Forms.Control.WmShowWindow(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmShowWindow(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
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)


Any insights as to what the problem could be and how we can fix it? I'd imagine alot of our users will start to upgrade their clients soon as well so a speedy response would be much appreciated.

Regards,
Johan