Microsoft pushed out KB5063878 on August 12th, and within hours, streamers started reporting that their NDI streams looked like garbage. Microsoft's own engineers confirmed on August 21st that the update breaks NDI receive mode by defaulting to RUDP instead of TCP/UDP, causing packet retransmissions that make your streams stutter.
The Real Problem (Not Microsoft's Corporate Bullshit)
Here's what's actually happening: The security update fucks with how Windows handles network packets for NDI streams. When your streaming app tries to receive video from another device, Windows now defaults to RUDP (Reliable User Datagram Protocol) instead of regular TCP or UDP. RUDP sounds good in theory - it's supposed to be more reliable - but in practice it causes packet retransmissions that make your streams look like shit.
This affects anyone using OBS Studio with NDI sources, NDI Tools, or any professional broadcasting setup that relies on network video streaming. Both Windows 11 24H2 (build 26100.4946) and Windows 10 systems are affected.
The 2-Minute Fix That Actually Works
Don't waste time with Microsoft's workarounds. Here's what you do:
- Open your NDI receiving application (OBS, NDI Tools, etc.)
- Find NDI settings - usually under Sources > NDI or Network settings
- Change NDI Receive Mode from RUDP to TCP - UDP works too but TCP is more stable
- Restart your streaming application - don't just refresh the source
If you can't find these settings in your app, download NDI Tools and use NDI Access Manager to force TCP mode system-wide. This fix has worked for hundreds of streamers on Reddit and costs exactly zero dollars.
Why Microsoft's "Official" Fix Is Garbage
Microsoft's official guidance suggests "adjusting NDI configuration" and "monitoring Windows release health." That's corporate speak for "we don't have a real solution yet, so figure it out yourself."
The company hasn't provided a timeline for an actual fix, which means you're stuck with this workaround until they release another cumulative update. Based on past performance, that could be weeks or months.
Production War Stories
I've seen corporate broadcasts go completely dark during live events because IT departments pushed this update without testing. One enterprise customer on Microsoft's forums reported losing a $50,000 product launch stream because the NDI cameras started dropping frames mid-presentation.
Educational institutions got hit hard too. Universities setting up hybrid classrooms for the fall semester found their multi-camera lecture setups unusable after the update. The fix above saved dozens of lecture halls from having to go back to single-camera setups.
The Bigger Picture Problem
This isn't just about NDI streaming - it's about Microsoft's testing process being completely fucked for professional workflows. They test against consumer scenarios (opening Word, browsing Facebook) but clearly don't test against professional broadcasting equipment.
Security researcher Kevin Beaumont pointed out that Microsoft's update testing focuses on common consumer applications while ignoring specialized professional software that enterprises actually depend on. When you're paying for Windows Pro licenses, you expect professional-grade testing.
What's Actually Coming Next
Microsoft's engineering team is "actively investigating" according to their Windows release health page, which in Microsoft speak means "we're aware of the problem but don't hold your breath for a quick fix."
Based on past update cycles, expect a fix in the September or October cumulative update. Until then, use the TCP workaround above - it's more reliable than rolling back the security update and leaving your system vulnerable.
