Microsoft has officially confirmed that the August 2025 Windows security update (notably KB5063878 for Windows 11 24H2 and KB5063709 for Windows 10 21H2/22H2) is responsible for causing severe stuttering, lag, and choppy audio/video in popular streaming applications such as OBS (Open Broadcaster Software) and NDI Tools, especially when using the Display Capture feature. The issue appears linked to the Reliable UDP (RUDP) protocol used by NDI; switching to TCP or standard UDP as the receive mode restores smoother streaming. Microsoft is investigating further and recommends this workaround until a more permanent fix is released.
Sources: Tom’s Guide, Reddit, Microsoft
Key Takeaways
– Impact on Creators: Users relying on NDI streaming workflows—especially those using “Display Capture”—are experiencing significant quality degradation in their streams.
– Temporary Fix Is Manual: Switching the NDI receive mode from RUDP to TCP or UDP alleviates the issue for now.
– Microsoft Is On It: The company has confirmed the problem publicly and is investigating a fix, though no patch is available yet.
In-Depth
Microsoft’s August 2025 security patch—specifically KB5063878 for Windows 11 and KB5063709 for Windows 10—has been flagged for causing serious streaming performance issues, particularly in setups using NDI (Network Device Interface) with OBS or NDI Tools. Users have reported “severe stuttering, lag, and choppy audio/video,” notably when Capture Display is enabled. The root cause appears to lie in NDI’s default use of RUDP (Reliable UDP), which fails under this update, while traffic via standard UDP or TCP remains stable.
As a stopgap, Microsoft recommends changing the NDI Receive Mode from RUDP to TCP or UDP. While this workaround restores normal streaming quality, it’s far from ideal for creators who depend on low-latency transmission over RUDP. Microsoft has publicly acknowledged the glitch—citing reports from Bleeping Computer and others—and is investigating, but no dedicated patch has been released yet. Until then, affected users must decide between the workaround or rolling back the update, both carrying trade-offs between stability and performance.