Hi,
Actually I've this problem, even if uninstalling and reinstalling:

MagicExceptionType: MagicException
Severity: Fatal
Message: Sorry, an unexpected error has occurred.
ActionToTake: The application will now close.
ExtraDetails:
InternalDetails: The task 'Initializing card data' failed to complete.
in WotC.MtGO.Client.Model.Core.TaskManager.<>cDisplayClass28_0.<RaiseCompletedEvent>b0(Object <p0>) in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\TaskManager.cs:riga 339
in System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
in System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
in System.Windows.Threading.DispatcherOperation.InvokeImpl()
in System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
in MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
in System.Windows.Threading.DispatcherOperation.Invoke()
in System.Windows.Threading.Dispatcher.ProcessQueue()
in System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
in MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
in MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
in System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
in System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
in System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
in MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
in MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
in MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
in System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
in System.Windows.Application.RunDispatcher(Object ignore)
in System.Windows.Application.RunInternal(Window window)
in Shiny.App.Main() in C:\CM\workspace\releasenext\source\windows\clients\Shiny\View\MainNavigation\obj\Release\App.g.cs:riga 52

Inner exception:MagicExceptionType: CardDataException
Severity: Fatal
Message: There is a critical error.
ActionToTake: The application will now close.
ExtraDetails:
InternalDetails: Error reading XML card data. This usually means that you have a corrupted install folder or registry. Please uninstall MTGO from the add/remove programs menu, and then reinstall the application from the MTGO website.
in WotC.MtGO.Client.Model.Core.CardDataManager.DoInitialize() in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\CardDataManager.cs:riga 1524
in WotC.MtGO.Client.Model.Core.LongRunningTask.TaskThread(Object state) in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\LongRunningTask.cs:riga 310
in System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
in System.Threading.ThreadHelper.ThreadStart(Object obj)

Inner exception:MagicExceptionType: CardDataException
Severity: Fatal
Message: There is a critical error.
ActionToTake: The application will now close.
ExtraDetails:
InternalDetails: Assertion failed: Card data not found at 'C:\Users\Casa\AppData\Local\Apps\2.0\QKYE7PMP.DBB\H3G258PH.H66\mtgo..tion80e21eca2a0e12580003.00044eccf4d447d04458\CardDataSource\MTGOV3CardData.xml'.
in WotC.MtGO.Client.Model.Core.CardDataManager.ResolveCardDataPaths() in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\CardDataManager.cs:riga 1422
in WotC.MtGO.Client.Model.Core.CardDataManager.DoInitialize() in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\CardDataManager.cs:riga 1524
in WotC.MtGO.Client.Model.Core.LongRunningTask.TaskThread(Object state) in C:\CM\workspace\releasenext\source\windows\clients\Shiny\Model\WotC.MtGO.Client.Model.Core\LongRunningTask.cs:riga 310
in System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
in System.Threading.ThreadHelper.ThreadStart(Object obj)