Introduction
Microsoft’s August 2025 Patch Tuesday introduced critical security fixes—but also severely disrupted NDI streaming. Users of OBS and NDI Tools reported serious stuttering, lag, and choppy audio/video following updates KB5063878 and KB5063709.
What’s Going Wrong?
- Affected updates: KB5063878 (Windows 11) and KB5063709 (Windows 10)
- Root issue: Breaks RUDP transport used by NDI for low-latency streaming
- Symptoms: Sudden frame drops, distorted audio, poor streaming quality
Who’s Impacted?
This issue affects streamers, AV professionals, educators, and content creators who rely on NDI tools across Windows environments.
Microsoft’s Response & Workaround
Microsoft confirmed the bug and is investigating. Meanwhile, NDI suggests switching from RUDP to Single TCP or UDP (Legacy) mode:
- Install NDI Tools
- Open NDI Access Manager
- Go to the Advanced tab
- Change Receive Mode to Single TCP or UDP
- Apply settings on all affected PCs
Why This Matters
- Disrupts live production and remote AV workflows
- Highlights need to test updates in critical environments
- Balance between security and reliability is crucial
Summary Table
| Issue | Details |
|---|---|
| KB Numbers | KB5063878 (Win11), KB5063709 (Win10) |
| Affected Apps | OBS, NDI Tools, NDI Display Capture |
| Cause | Broken RUDP transport in Windows networking stack |
| Workaround | Switch to TCP or UDP mode in NDI Access Manager |
| Status | Under investigation by Microsoft |
