NDI stutter after August 2025 Windows updates: switch NDI Receive Mode to TCP or UDP

Microsoft has acknowledged that this month’s cumulative update has an ugly side effect for creators and broadcasters: Windows 11 and Windows 10 systems that installed the August 12, 2025 security patches can exhibit severe stuttering and choppy audio/video in popular streaming tools that rely on NDI, including OBS Studio, especially when Display Capture is enabled. Redmond flagged the regression in its Windows Release Health tracker and pointed to vendor guidance that identifies NDI’s default RUDP transport as the trigger, with UDP (Legacy) and Single TCP remaining unaffected. The company says it is investigating; in the meantime, the recommended mitigation is to switch NDI’s Receive Mode away from RUDP on affected PCs.

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Overview​

The August 2025 Patch Tuesday updates were already a heavyweight security drop—Microsoft fixed more than 100 vulnerabilities and closed a publicly disclosed zero-day in Windows Kerberos—before performance complaints from streamers and AV teams started piling up. Those reports coalesced around one pattern: installations that had taken the Windows 11 24H2 cumulative update KB5063878 or the Windows 10 22H2/21H2 cumulative update KB5063709 saw NDI-based workflows turn unreliable overnight. Microsoft has now confirmed the behavior, tied it to NDI’s RUDP mode, and linked to NDI’s step-by-step workaround while it works on a permanent fix. (bleepingcomputer.com, learn.microsoft.com)
As a reminder of the wider patch context, Microsoft’s August 12 slate addressed 107 vulnerabilities, including CVE‑2025‑53779, a Kerberos issue that could allow an authenticated attacker to escalate privileges to domain admin under specific conditions. That security weight makes any rollback decision nontrivial: stability matters to production crews, but skipping security fixes—especially one that touches Active Directory—carries real risk.

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What Microsoft actually confirmed​

Microsoft’s Windows 11 24H2 Release Health page lists a new entry titled “Problems with NDI streaming performance after installing the August 2025 update.” The symptom description reads: “Severe stuttering, lag, and choppy audio/video might occur when using NDI … The issue affects streaming apps, including OBS and NDI Tools, especially when ‘Display Capture’ is enabled on the source PC.” Microsoft adds that the problem “persists even under low bandwidth conditions,” which hints at timing and buffering, not raw throughput. The same entry notes the recommended workaround—change NDI’s Receive Mode to use TCP or UDP instead of RUDP—and says engineering is investigating.
Microsoft lists the following platforms as affected: Windows 11 version 24H2 (KB5063878) and Windows 10 version 22H2/21H2 (KB5063709). The Windows 10 22H2 Release Health page mirrors the advisory, including the RUDP-only scope and the same mitigation.

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The short version for creators: what’s broken, what still works​

• Impacted: NDI streams that use the default RUDP transport after installing KB5063878 (Windows 11 24H2) or KB5063709 (Windows 10 22H2/21H2). Severe stutter and choppy A/V are common symptoms, and the issue is especially visible when Display Capture is in the scene on the source PC.
• Not impacted in reported tests: NDI flows using UDP (Legacy) or Single TCP transports. Switching to either mode can restore reliable performance while maintaining the Windows security updates.
• Affected apps: OBS Studio and NDI Tools are explicitly named by Microsoft; any application that uses NDI over RUDP is potentially affected.

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Why NDI’s RUDP is the flashpoint​

NDI supports multiple wire transports to balance latency and reliability:

• RUDP (Reliable UDP) is NDI’s modern default in many setups. It adds application‑layer reliability and pacing over UDP to avoid head‑of‑line blocking while keeping latency tight.
• UDP (Legacy) sends unacknowledged datagrams—lowest overhead and lowest latency, but no retransmissions.
• Single TCP is the most conservative option: ordered and reliable, though it can tolerate jitter and loss poorly due to head‑of‑line blocking.

NDI’s vendor note says the regression “occurs only with RUDP connections, while traffic sent or received using UDP or Single‑TCP remains unaffected.” That aligns with field reports that changing the Receive Mode is immediately stabilizing.
While Microsoft has not published a root‑cause analysis yet, a plausible reading is that subtle timing, buffering, or scheduler changes in the networking stack (or in related kernel paths) are knocking RUDP’s congestion and retransmission heuristics off balance. That would explain why symptoms present even on low‑utilization links and why UDP and TCP paths remain clean. This should still be treated as informed inference until Microsoft releases technical details.

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The precise updates and dates to know​

• Windows 11 version 24H2: KB5063878 (OS Build 26100.4946), released August 12, 2025. Microsoft added the NDI issue to Release Health on August 21, 2025.
• Windows 10 version 22H2/21H2: KB5063709 (OS Builds 19045.6216/19044.6216), released August 12, 2025, with a matching Release Health item for the NDI regression.

These entries are current as of August 23, 2025 and still marked “Confirmed” with Microsoft’s investigation ongoing.

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Step‑by‑step: the vendor‑aligned workaround that actually helps​

NDI’s guidance, which Microsoft references in Release Health, is straightforward. It does not require uninstalling August’s security updates.

• Download and install the free NDI Tools pack.
• Launch NDI Access Manager on the receiving computer.
• Open the Advanced tab.
• Change Receive Mode from RUDP (default) to Single TCP or UDP.
• Click OK, then restart any NDI‑receiving applications (OBS, Studio Monitor, vMix) so they read the updated configuration.
• Repeat the change on other participating PCs as needed.

This can be done in minutes and is reversible once a Windows fix ships. If you have distributed teams or remote guests, coordinate the change during a rehearsal or maintenance window. (learn.microsoft.com, docs.ndi.video)

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Choosing between Single TCP and UDP: practical trade‑offs​

• Single TCP
• Best for reliability across complex networks and gear that mishandles UDP variants.
• Potential downsides: added latency and head‑of‑line blocking if there’s packet loss or microbursts.
• Good default if you must stabilize quickly and can afford a few extra milliseconds end‑to‑end.
• UDP (Legacy)
• Lowest latency on a clean, dedicated LAN.
• No retransmissions; any drop is visible unless your production workflow buffers it.
• Best where you control the switching fabric and can guarantee low loss and jitter.

Whichever path you choose, retest your scenes—especially those with Display Capture—and confirm lip‑sync and frame pacing before going live.

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Don’t forget the security context: why uninstalling the KB is a last resort​

There is a temptation to remove KB5063878/KB5063709 to “get back to normal.” That can work, but it comes with a cost: you’ll also remove fixes for more than 100 security issues, including a Kerberos flaw that, under specific conditions, can be part of a chain to domain compromise. If your environment uses Active Directory and you manage more than a single PC, that’s not a trade‑off to make lightly.
If rollback is the only way to save a mission‑critical live event, follow change‑control rigor and plan to reinstall the security update immediately after. On Windows 11 24H2, combined SSU+LCU packages can’t be removed using the wusa.exe /uninstall switch; Microsoft’s documentation notes you must use DISM /Remove‑Package with the LCU package identity instead. That is an advanced operation; test before applying at scale.

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What else went wrong in August—and why it matters here​

The NDI regression is not an isolated headline. Within days of Patch Tuesday, Microsoft also acknowledged a separate bug that broke Reset this PC and other recovery operations on some Windows 10 installations and older Windows 11 versions (23H2/22H2). Redmond pushed an out‑of‑band update to address those recovery failures, underscoring how quickly this month’s release cycle has been evolving.
In parallel, independent testers and the tech press have reported storage‑related anomalies on certain SSDs after KB5063878, with early suspicion falling on specific controller families. Microsoft has not formally attributed a root cause there, but the pattern of multiple high‑impact issues in the same patch wave is a sober reminder for streamers and IT alike: keep a rollback plan, and stage updates with adequate soak time before show day.

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For OBS and NDI users: quick wins to stabilize today​

• Switch NDI Receive Mode away from RUDP on all affected endpoints. Validate scene performance with Display Capture enabled, since that code path exhibits the worst symptoms. (learn.microsoft.com, docs.ndi.video)
• Prefer window or game capture when viable. While Display Capture is convenient, it can be more sensitive to OS and graphics‑stack changes.
• If latency budget allows, start with Single TCP. If you’re cutting cameras on a tightly timed network and can guarantee low loss, test UDP (Legacy) for lower delay.
• Restart NDI‑receiving apps after changing Access Manager settings; many clients read configuration at startup and won’t pick up changes in flight.
• If a remote contributor cannot change settings, consider standing up a bridge or relay on your LAN that receives via TCP and forwards to your mixing system, or consult the NDI docs for topology options.

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For IT administrators: a controlled response for fleets​

Enterprise AV and edu environments often run NDI for lecture capture, overflow rooms, or corporate town halls. Here’s a pragmatic playbook:

• Inventory which production paths use NDI and, specifically, which receivers are set to RUDP. Start with studios and rooms that rely on Display Capture.
• Push an operational advisory: instruct staff to change NDI Receive Mode to Single TCP or UDP on affected hosts, and to restart their NDI applications after the change.
• Avoid wholesale uninstall of security updates. If you must roll back on a subset for a short‑fused event, isolate those devices, document exceptions, and schedule re‑patching ASAP.
• If you manage updates via WSUS, note that Microsoft resolved a delivery failure earlier in the cycle (0x80240069) for KB5063878; a simple re‑sync may be required if you encountered it mid‑week. (learn.microsoft.com, bleepingcomputer.com)
• Update runbooks to add an “NDI transport check” to pre‑show checklists until a permanent fix ships.

This is also a teachable moment for change management: Patch Tuesday changes should not land on control‑room computers the same day as a live show. Keep a staging ring and at least a one‑week soak before deploying to production‑critical endpoints.

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Why Display Capture seems to make things worse​

Microsoft’s advisory explicitly calls out a sharper impact “when ‘Display Capture’ is enabled on the source PC.” That aligns with how Display Capture increases the amount and cadence of screen‑scraped frames, amplifying any timing jitter in the capture‑encode‑transport pipeline. When RUDP’s pacing and retransmission heuristics go slightly out of tune, high‑frequency, full‑screen frame flows become the first to show stutter and A/V desync. Switching to Single TCP or UDP can remove that sensitive middle layer and restore consistent pacing.

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What a permanent fix will likely look like​

Microsoft says it’s investigating. Given the clear transport boundary (RUDP only) and cross‑version impact (Windows 10 and 11), the fix could land in the networking stack, kernel scheduling, or a compatibility shim tuned specifically for NDI’s RUDP behavior. Because Redmond linked directly to NDI’s vendor documentation, it’s reasonable to expect coordination between the platform and vendor on a resolution. If history is a guide, an out‑of‑band update or a cumulative update with a documented mitigation may arrive in the coming weeks. Until then, the Receive Mode switch is the safe route.

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Verifying whether you’re affected​

• Windows 11 (24H2): Check if KB5063878 is installed.
• Windows 10 (22H2/21H2): Check if KB5063709 is installed.
• In NDI Access Manager, confirm whether the receiver is set to the default RUDP mode.

The NDI FAQ page includes a helpful checklist in the “Check if you have the affected update installed” section, along with the direct mitigation steps.

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If you absolutely must roll back the KB​

Rolling back is not recommended unless business‑critical production is at risk. If you proceed:

• Use Windows Settings > Windows Update > Update History > Uninstall updates to remove the relevant security update (KB5063878 or KB5063709). Be aware that Windows may reinstall the update later depending on your policies.
• On Windows 11 24H2, the cumulative update includes the servicing stack; Microsoft notes wusa.exe /uninstall won’t work on the combined package. Use DISM /Remove‑Package with the exact LCU package name if you must remove it, and test first.

Remember: removing security updates reopens known vulnerabilities patched this month, including the publicly disclosed Kerberos issue. Plan compensating controls and reinstall security updates as soon as a streaming‑safe fix is available.

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How this compares to prior Windows update snafus​

It wouldn’t be the first time multimedia or networking stacks showed regressions after cumulative updates, but this cycle stands out because of its breadth: in the span of ten days, Microsoft acknowledged the NDI performance bug, resolved a WSUS delivery failure for KB5063878, and shipped an emergency fix to repair recovery operations broken on some pre‑24H2 clients. Pair that with third‑party reports of SSD behavior anomalies on certain controllers under heavy I/O, and it’s clear August demanded a higher‑than‑average level of vigilance from Windows power users and IT pros alike. (learn.microsoft.com, bleepingcomputer.com, windowscentral.com)

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Recommendations we stand behind​

• Prioritize the Receive Mode change. It restores NDI stability without sacrificing crucial security fixes from August Patch Tuesday.
• Stage updates. Keep a “production ring” for broadcast and control‑room PCs that receives cumulative updates only after a soak period on noncritical machines.
• Document NDI transport choices. For each studio or classroom, record whether Single TCP or UDP is in use, and why. This speeds up troubleshooting if conditions change.
• Monitor Release Health. Microsoft has been updating its status pages quickly this month; a fix or Known Issue Rollback could appear before the next Patch Tuesday.

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What to watch next​

• A Windows fix that restores RUDP stability. Given the vendor confirmation and cross‑version scope, expect the resolution to appear in a cumulative update or as an out‑of‑band patch if the impact warrants it.
• Any NDI software updates that adjust RUDP tuning for changed Windows behaviors. While Microsoft owns the OS layer, vendors sometimes add adaptive logic to tolerate platform shifts.
• Additional advisories. August already saw a WSUS installation failure get fixed mid‑cycle, plus an OOB update for recovery failures on older Windows builds. Keep an eye on both Windows 11 24H2 and Windows 10 22H2 status pages. (learn.microsoft.com, bleepingcomputer.com)

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SEO cheatsheet: terms people are searching for​

• Windows 11 KB5063878 streaming stutter
• OBS NDI lag after Windows update
• NDI RUDP performance issue Windows 10 KB5063709
• Display Capture stutter after Patch Tuesday
• How to change NDI Receive Mode to TCP or UDP

Use these terms to find peers discussing the same symptoms and to track when Microsoft ships the fix.

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Bottom line​

This is a real and reproducible regression: after the August 12, 2025 cumulative updates, Windows 11 24H2 and Windows 10 22H2/21H2 devices can exhibit severe NDI stutter and choppy audio/video when RUDP is in use—most notably with OBS and Display Capture. Microsoft has confirmed the problem and is investigating. Until a fix lands, the reliable path is to keep the security updates installed and change NDI’s Receive Mode to Single TCP or UDP. That swap preserves stability for live production without giving up August’s critical security protections, including the Kerberos zero‑day fix. Test, document, and keep an eye on Release Health for the all‑clear. (learn.microsoft.com, docs.ndi.video, bleepingcomputer.com)

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Source: Tom's Guide Microsoft confirms latest Windows 11 update is tanking streaming app performance