It happened again this morning, approximately 24 hours after uploading updates to all 5 sites.

The full text of the error message follows.  Does this provide any clues as to what's going on?

Server Error in '/' Application.
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GDI+ is not properly initialized (internal GDI+ error).
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Runtime.InteropServices.ExternalException: GDI+ is not properly initialized (internal GDI+ error).

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. 

Stack Trace:


[ExternalException (0x80004005): GDI+ is not properly initialized (internal GDI+ error).]
   System.Drawing.Bitmap..ctor(Stream stream) +393850
   System.Drawing.ToolboxBitmapAttribute..cctor() +219

[TypeInitializationException: The type initializer for 'System.Drawing.ToolboxBitmapAttribute' threw an exception.]
   System.Reflection.CustomAttribute._CreateCaObject(Void* pModule, Void* pCtor, Byte** ppBlob, Byte* pEndBlob, Int32* pcNamedArgs) +0
   System.Reflection.CustomAttribute.CreateCaObject(Module module, RuntimeMethodHandle ctor, IntPtr& blob, IntPtr blobEnd, Int32& namedArgs) +104
   System.Reflection.CustomAttribute.GetCustomAttributes(Module decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes) +490
   System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeType type, RuntimeType caType, Boolean inherit) +258
   System.RuntimeType.GetCustomAttributes(Type attributeType, Boolean inherit) +63
   System.ComponentModel.ReflectTypeDescriptionProvider.ReflectGetAttributes(Type type) +262
   System.ComponentModel.ReflectedTypeData.GetAttributes() +36
   System.ComponentModel.DefaultTypeDescriptor.System.ComponentModel.ICustomTypeDescriptor.GetAttributes() +50
   System.ComponentModel.TypeDescriptor.GetAttributes(Type componentType) +26
   System.Web.UI.ViewStateModeByIdAttribute.IsEnabled(Type type) +46
   System.Web.UI.Control.SaveViewStateRecursive() +117
   System.Web.UI.Control.SaveViewStateRecursive() +156
   System.Web.UI.Control.SaveViewStateRecursive() +156
   System.Web.UI.Control.SaveViewStateRecursive() +156
   System.Web.UI.Control.SaveViewStateRecursive() +156
   System.Web.UI.Page.SaveAllState() +466
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2357