Streaming

NDI source not showing up? How to fix it

By Mambo Mutinda · Founder & CEO, TajiCast

31 July 2026 · Updated 8 September 2026

You set up an NDI source — a camera, a graphics machine, a scripture feed — and it is simply not there in the dropdown. Blank list, no source, no explanation. The good news is that invisible NDI sources come from a short list of causes, and each has a definite fix. This walks through them in the order worth trying.

First, how NDI finds things

NDI sends video over your local network, and devices discover each other automatically, as long as they are on the same network and nothing blocks them.

That is the whole mechanism, and it is why the failure is so opaque: when a source does not appear, the software has nothing to report. It did not fail to connect — it never saw anything to connect to. So the fault is almost never in the switcher you are staring at. New to this? Start with NDI for churches.

The quick table

Work down it in order. The first three account for most cases and none of them announce themselves.

1. The firewall

The most common cause, and the least obvious, because nothing warns you.

NDI discovery uses network broadcast traffic that Windows Firewall blocks by default for applications it does not recognise. Both the sender and the receiver need to be allowed.

1. Open Windows SecurityGo to Windows Security → Firewall & network protection → Allow an app through firewall.
2. Find both applicationsLook for your switcher (OBS or vMix) and your sending application.
3. Tick both networksAllow each on both Private and Domain. If an application is missing entirely, add it with "Allow another app".

2. Are they really on the same network?

Two machines can be in the same room, on the same wifi name, and still be on different subnets that cannot see each other.

• Guest networks are the usual culprit. Many are deliberately configured to isolate devices from one another — good security, fatal to NDI.
• Check the addresses. Run ipconfig on both machines. The first three groups of the IPv4 address should match: 192.168.1.x and 192.168.1.y can see each other; 192.168.1.x and 192.168.8.y cannot.
• Two routers, one building. Common in churches that added wifi later. Anything plugged into the second router may be on its own subnet.

3. Get off wifi

NDI runs over wifi. It should not be trusted there for anything going on air.

Discovery packets get dropped, so sources flicker in and out of the list, and the video stutters in a way that is very visible on a stream. If your source appears sometimes and vanishes other times, this is almost certainly why.

A cheap gigabit switch and two Ethernet cables solve it permanently, and it is among the best-value purchases in a church media booth.

4. In OBS: is the plugin actually loaded?

vMix has NDI built in. OBS does not — it needs the community NDI plugin, currently maintained by DistroAV.

The trap is version matching: install a plugin built for a different OBS release and it fails silently, with no error and no NDI Source in the list. If "NDI Source" is missing from the source menu entirely, the plugin has not loaded, whatever the installer said.

1. Close OBS completelyQuit before installing, so the plugin registers cleanly.
2. Match the versionsDownload the plugin build for your exact OBS version and operating system.
3. Reinstall and reopenThen check the source menu for "NDI Source".

5. Is the sender actually sending?

Worth checking before you take the network apart. In the sending application, confirm NDI output is switched on for the display you mean to broadcast — in TajiCast, that is in the broadcast settings for the output you want on the stream.

A sender that is running but not outputting looks exactly like a network fault from the far end.

It appears, but it is black

A different problem with a different cause. The discovery worked; the picture did not.

• Bandwidth mode too low. Set it to Highest for anything on the program feed.
• No alpha channel. A lower-third that should key over the camera needs the sender outputting a transparent background. Without it you get a black rectangle instead of a keyed graphic.

It appears, but it stutters

• Move off wifi, as above.
• Avoid several full-quality NDI streams over one modest switch. Gigabit wired handles a few comfortably; a shared 100 Mbps switch does not.
• Match the sender's resolution to your switcher's canvas so nothing is being rescaled in real time.

Still nothing?

Restart both applications, then both machines. NDI discovery caches, and a stale cache after a network change is real, if unsatisfying.

Then simplify until it works: put both machines on the same switch with nothing else attached. If the source appears, add the rest of the network back one piece at a time. It is slow, and it is faster than guessing.

The takeaway

• Firewall, subnet, wifi — in that order. They cause most invisible sources and none of them announce themselves.
• OBS needs a plugin matched to its version; vMix does not.
• A black source or a stuttering one is a different fault: bandwidth, alpha, or the network being asked to carry too much.

Related: NDI for churches · TajiCast for vMix · TajiCast for OBS