It works if you install the NDI Tool 5.0 .. ot me it's occurred so yesterday evening
I had the same issue so I installed NDI Tool 5.0 and uninstalled the old runtime, but I cannot get OBS Studio to look at the Version 5 runtime. When I launch I get a popup saying it couldn't be found, and I have this in the logs:
01:22:37.639: [obs-ndi] hello ! (version 4.10.0)
01:22:37.639: [obs-ndi] Trying 'C:\Program Files\NewTek\NDI 4 Runtime\v4'
01:22:37.639: [obs-ndi] Can't find the NDI library
01:22:41.591: Failed to initialize module 'obs-ndi.dll'
Even tried uninstalling OBS and re-installing, deleted everything out of the Windows prefetch folder, I cannot figure out where it is storing to look there for the runtime.