A source keeps reconnecting
A source that drops out is not a crash: InterDirector keeps retrying it on its own, at intervals that stretch to thirty seconds, and its card says Reconnecting while it does. Your other sources, and any output that is running, carry on unaffected.
What to check
- The cable or connection. For a camera or capture device, reseat the USB or Thunderbolt connection. A dock or hub that also carries other high-bandwidth traffic (another camera, a fast drive) can be the cause even when the cable itself is fine.
- Power. Some capture devices and cameras drop out under power-saving settings, particularly on a laptop running from battery. Check macOS’s own energy settings for the device or port, if it has any.
- The network, for NDI. An NDI sender that keeps dropping is usually a Wi-Fi link straining under the bandwidth, or a switch somewhere in between that cannot keep up. A wired connection to both the sender and this Mac is the first thing to try.
If it will not come back
Stop the source by hand and start it again; that resets the retry from the beginning rather than waiting out however many attempts have already run. If it still will not connect, the source itself (the camera, the capture device, the NDI sender) is the next place to look, outside InterDirector.
See also
I don’t see any NDI sources, if the problem is that a source never appears in the first place, rather than one that drops after it was working.