dotnet/wpf · critical · OutOfMemoryException

E_OUTOFMEMORY

E_OUTOFMEMORY

Error message

OutOfMemoryException

What it means

MediaContext.NotifyPartitionIsZombie maps the render-thread failure HRESULT to a managed exception. When the failure code is E_OUTOFMEMORY it throws a bare OutOfMemoryException, indicating the render/UCE partition went zombie because the renderer ran out of memory.

Solutions

1. Free visual resources: unload large images (set Source=null), call GC.Collect after releases, and reduce simultaneous large bitmaps.
2. Switch to a 64-bit process to remove the 2GB address-space limit.
3. Use DecodePixelWidth/Height to downscale images at decode time instead of full-resolution bitmaps.
4. Profile memory (dotMemory/PerfMon) for leaks around Visuals, Images and bitmaps; check for the real OutOfMemoryException inner cause.

Example fix

// before
img.Source = new BitmapImage(new Uri("huge.jpg")); // full-res decode
// after
var bmp = new BitmapImage();
bmp.DecodePixelWidth = 800; // decode scaled-down
bmp.BeginInit();
bmp.UriSource = new Uri("huge.jpg");
bmp.EndInit();
img.Source = bmp;

// Pre-check process memory before loading large imagery:
using var p = Process.GetCurrentProcess();
if (p.PagedMemorySize64 > 1L * 1024 * 1024 * 1024) FreeUnusedImages();

try { LoadLargeImages(); }
catch (OutOfMemoryException) { FreeUnusedImages(); GC.Collect(); GC.WaitForPendingFinalizers(); RetryWithDownscaling(); }

When it happens

Trigger: The render thread reports partition failure with HRESULT E_OUTOFMEMORY (via NotifySyncChannelMessage or NotifyChannelMessage) — usually after huge image allocations, excessive bitmap caching, or desktop heap / video-memory pressure.

Common situations: Loading many large images simultaneously, huge WriteableBitmap/RenderTargetBitmap allocations, memory leaks in visual-tree content, 32-bit process address-space exhaustion.

Related errors

• D3DERR_OUTOFVIDEOMEMORY
• WGXERR_UCE_RENDERTHREADFAILURE
• OutOfMemoryException
• SR.MediaContext_NoBadShaderHandler
• Win32Exception (native Win32 error from DuplicateHandle…

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/9c72312c8b235c75. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/MediaContext.cs:424

        /// <summary>
        /// The partition this media context is connected to went into
        /// zombie state. This means either an unhandled batch processing,
        /// rendering or presentation error and will require us to reconnect.
        /// </summary>
        private void NotifyPartitionIsZombie(int failureCode)
        {
            //
            // We only get back these kinds of notification:-
            // For all OOM cases, we get E_OUTOFMEMORY.
            // For all OOVM cases, we get D3DERR_OUTOFVIDEOMEMORY and
            // for all other errors we get WGXERR_UCE_RENDERTHREADFAILURE.
            //

            switch (failureCode)
            {
            case HRESULT.E_OUTOFMEMORY:
                throw new System.OutOfMemoryException();
            case HRESULT.D3DERR_OUTOFVIDEOMEMORY:
                throw new System.OutOfMemoryException(SR.MediaContext_OutOfVideoMemory);
            default:
                throw new System.InvalidOperationException(SR.MediaContext_RenderThreadError);
            }
        }

        /// <summary>
        /// The back channel processed a malformed packet and so gives
        /// the notification of invalid packet.
        /// </summary>
        private void HandleInvalidPacketNotification()
        {
            //
            // -
            // For now we ignore the packet and continue processing
            // other packets. In future, we could also close this channel.
            //

View on GitHub (pinned to 81131a70a4)