# Traffic Drops After Windows Update

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Windows has a released a patch for the unexpected drop in traffic on RUDP connections. The patch is currently available for both Windows 10 and 11. You can find more information on the [Windows Support Page](https://support.microsoft.com/en-us/topic/september-9-2025-kb5065429-os-builds-19044-6332-and-19045-6332-b343e907-4f50-41d9-80f8-519490551b91)
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There is currently a Windows Security Update that can cause NDI traffic to drop unexpectedly on computers with this update installed.

The affected updates are:

**Windows 11 – KB5063878**\
<https://support.microsoft.com/en-au/topic/august-12-2025-kb5063878-os-build-26100-4946-e4b87262-75c8-4fef-9df7-4a18099ee294>

**Windows 10 – KB5063709**\
<https://support.microsoft.com/en-au/topic/august-12-2025-kb5063709-os-builds-19044-6216-and-19045-6216-96d99cf6-f8b5-4798-9892-4e3eb8f11548>

### Symptoms

When this update is installed, NDI connections may drop unexpectedly during use. The problem occurs **only with RUDP** connections, while traffic sent or received using **UDP or Single-TCP remains unaffected**.

#### Check if you have the affected update installed

1. Open **Settings** in Windows.
2. Select **Windows Update**.
3. Select **Update History**.
4. Select **Uninstall Updates**.
5. Look for **Security Update for Microsoft Windows (KB5063878 or KB5063709)**.

If you don’t have it installed, we recommend delaying installation until a fix is released. However, depending on your update settings, it may install automatically in the future.

### How to solve

**Option 1 (recommended):**\
Manually change the NDI Receive Mode to use TCP or UDP instead of RUDP.

1. Download and install the free [NDI Tools pack](https://ndi.video/tools/).
2. Launch the **NDI Access Manager** app.
3. Go to the **Advanced** tab.
4. Change **Receive Mode** to **Single TCP** or **UDP**, then press OK.
5. Repeat on any other affected computers.

**Option 2:**\
Uninstall the Windows Security Update.

1. Open **Settings** in Windows.
2. Select **Windows Update**.
3. Select **Update History**.
4. Select **Uninstall Updates**.
5. Find **Security Update for Microsoft Windows (KB5063878 or KB5063709)** and click **Uninstall**.

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Windows may reinstall the update at a later date, so Option 1 is generally preferred unless you rely on workflows that specifically require RUDP.
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