Originally Posted by: kross 
I've had this happen to me several times. NDI feeds show up perfectly in Studio Monitor. It happens when starting vMix or reloading a project. I will sometimes get nothing but black for all of my NDI sources (I have 4). If I restart vMix enough times it finally works, and then everything is fine for the rest of the session. It doesn't happen every time, but it's an annoyance when it does.
vMix NDI Input freezes after ~4 hours – source remains visible, but new NDI input is blank
---
Hi everyone,
I am experiencing a recurring NDI issue with vMix and an OBSBOT Tail 2 PTZ camera.
The problem has happened several times, and the behavior is very similar each time.
### System / Setup
* vMix: vMix 29.0.0.48
* Camera: OBSBOT Tail 2
* NDI: Camera is outputting NDI over the LAN
* Resolution: 1080p59.94
* Network: Gigabit Ethernet
* Windows PC
* CPU: Intel i7-14700K
* RAM: 64 GB DDR4-3200
* GPU: NVIDIA RTX 5070 TI
* vMix is running continuously for several hours.
### The problem
After approximately **4 hours of continuous operation**, one of the OBSBOT NDI inputs in vMix suddenly freezes.
The video freezes on the **last received frame**.
vMix itself does NOT freeze. The vMix interface remains responsive and I can continue operating the other inputs.
The OBSBOT camera itself also appears to continue working.
### What I found when the problem occurs
The important part is that vMix can still **see/discover the OBSBOT NDI source**.
However:
1. The existing NDI input remains frozen on the last frame.
2. Resetting the existing input does not restore the video.
3. Deleting the input and creating a **new NDI input using the same OBSBOT NDI source** results in a **blank screen**.
4. The source is still visible/selectable in the NDI source list.
5. So vMix can discover the NDI source, but it cannot display/receive new video frames from it.
At the same time, I can still use **NDI Studio Monitor to view the same OBSBOT NDI source**, so the camera appears to still be transmitting NDI correctly.
The behavior is essentially:
```text
OBSBOT Tail 2
|
+---- NDI Studio Monitor -> VIDEO OK
|
+---- vMix
|
+---- Existing Input -> LAST FRAME FROZEN
|
+---- New NDI Input -> BLANK SCREEN
```
### This has happened multiple times
This is not a one-time occurrence. I have experienced the same behavior several times, generally after the camera/vMix setup has been running for around **4 hours**.
Because the source remains visible in vMix but the video cannot be received even by a newly created NDI input, I am wondering whether the problem could be related to the **vMix NDI receiving/decoding subsystem**, NDI runtime, or a resource issue that develops during long-running sessions.
### Memory usage
I have also observed high system memory usage during some sessions.
At one point:
* System RAM usage reached approximately **97%**
* vMix was using approximately **22 GB RAM**
I am not yet certain whether this is related to the NDI failure, but I am mentioning it because the failure appears after several hours of continuous operation.
### Things I have already checked
* vMix remains responsive when the NDI video freezes.
* Resetting the existing NDI input does not fix it.
* Creating a new NDI input using the same source results in a blank screen.（Source is viewable until you restart vmix)
* The OBSBOT NDI source remains visible/selectable in vMix.
* NDI Studio Monitor can still receive/view the same OBSBOT source when the vMix input is stuck.
I have also seen some unrelated Windows Event Viewer entries involving Intel DSA, DPTF and VBScript, but I do not currently have evidence that these are related to the NDI issue.
### My main questions
1. Does vMix use a persistent NDI receiver/decoder instance that could become stuck after several hours?
2. Is there a way to completely restart/reinitialize the NDI receiving subsystem inside vMix without restarting vMix?
3. Could high memory usage cause this type of behavior where NDI discovery still works but video reception/decoding stops?
4. Are there any known issues with long-running OBSBOT Tail 2 NDI sources in vMix?
5. Is there any vMix/NDI diagnostic log that I can collect when this happens?
I would appreciate any advice on how to diagnose this further.
Thanks!
