Fusion Studio and Decklink Mini Monitor 4K no output

In the last hour I uninstall Fusion Studio 20 beta 3 and installed beta 4. In beta 4, my Decklink Mini Monitor 4K appears in the preferences under Video Monitoring, but the nodes don't have the assignment button for it. Whereas in any previous version of Fusion Studio it had three or four buttons (four if I had a viewer window opened in the second monitor), now I have only two buttons, with a third one only if I open a viewer window, but no button for the Decklink.

Also, no matter what resolution I set the Decklink to in the preferences, if I close Fusion Studio and later open it again, it will default to 525i59.94 NTSC. Curiously, it does save the output pixel format, but not the video format.

I didn't see anyone reporting this, and I don't think I ever had to do anything specific after installing previous versions of Fusion Studio to make the Decklink work, it was just there for any project I opened.

It does work fine in Resolve Studio 20 beta 4.

Hopefully this will get resolved soon, otherwise I need to uninstall beta 4 and install beta 3.

Same problem.

This bug persists in the release version.

Do I have to go back to beta 3?

This time I skipped the beta version and put in the release version, but I don't have the same problem.

How about resetting Fusion.prefs?

1. Close Fusion Studio.
2. Rename Fusion.prefs to Fusion.prefs.bk.
3. Launch Fusion Studio.

This time I skipped the beta version and put in the release version, but I don't have the same problem.

How about resetting Fusion.prefs?

1. Close Fusion Studio.
2. Rename Fusion.prefs to Fusion.prefs.bk.
3. Launch Fusion Studio.

Thanks, but it didn't work. Same thing happens.

I had also tried uninstalling and then reinstalling Desktop Video 14.5, all with reboots in between of course.

Nobody else is having this problem? I find it hard to believe, after all, it was perfectly fine up to beta 3, and beta 4 broke it, without me opening my PC, or making any drastic change to Windows.

Did you clean the registry before the reboot? When you're clutching at straws, you may as well grab as big a handful as you can.

Did you clean the registry before the reboot? When you're clutching at straws, you may as well grab as big a handful as you can.

Sorry, are you referring to the Windows registry? I don’t touch that unless there’s a very good reason and I know exactly what I’m doing. I don’t use 3rd party tools because I’ve had terrible results with them in the past.

Well, now I'm really frustrated. I spent a lot of time uninstalling everything Blackmagic from my C drive, and went beyond the uninstallers, I deleted "C:\ProgramData\Blackmagic Design", "C:\Program Files\Blackmagic Design", and "C:\Users\[user]\AppData\Roaming\Blackmagic Design". I did a search with Agent Ransack, which does a real search, not checking the crappy Windows index, and there was nothing left except the dlls that OBS Studio comes with for the Decklink, and the decklink files that are inside the Unreal Engine installation, all of which are from when I first built this machine. But there was nothing Blackmagic left.

After a reboot, I installed Desktop Video 14.5, which forced to reboot, and then installed Fusion Studio 20 release, rebooted, and launched. It asked me for the license code, so it was the same as fresh install. I created a solid background to see if the view buttons were at the bottom of the node, and I saw 3, so I thought great, it worked. But no, it was because Monitor output was enabled, since the preferences had been cleared. Once I disabled Monitor Output, only two dots/buttons remained, for viewer 1 and 2. Just as before, the Decklink shows in the Video Monitoring preferences, always as 525i59.94 NTSC, which you can change but it will go back to that next time you close and then open Fusion again.

Also just as before, the Decklink works perfectly fine in Resolve Studio. This is getting really frustrating. Someone from Blackmagic replied to my email on Friday but I haven't heard anything back.

Obviously the card is not the problem, since it works perfectly fine in Resolve Studio, and even in OBS Studio, even if it only goes up to 1080p but that's probably a limitation in OBS Studio.

Any suggestions would be very appreciated, especially when I'm trying to redo my project in HDR, and we know that I can't do much of anything without previewing via an HDR card and TV set. I can't even get an idea using a viewer window, because it's going to display Rec.2020 inside sRGB, so the gamma is wrong, and the chroma is worse.

And importing a Fusion comp into the Fusion page inside Resolve is also broken.

If anyone has any suggestions, I would really appreciate it. I find it extremely odd that after uninstalling and cleaning my PC from everything Blackmagic, and reinstalling everything again, this problem persists. And I find it even more odd that nobody else is posting about it. But if there's anything different in my system as opposed to everybody else's, I really cannot figure out what it is.

If Resolve wouldn't work with it, then obviously something's wrong with the card. Easy. But Resolve works fine, and Fusion Studio doesn't, but it's not that it doesn't see the card, because it shows in the Video Monitoring preferences, but the nodes don't show the dot button for it. So that is very perplexing to me. Why does Fusion know that there's a Decklink card, but doesn't show the dot button for it?

If it was something that Fusion screwed up, then why nobody else is posting about it?

As I was saying I have the same problem, what I haven't tried yet is changing the pci-e slot, you can try this.

As I was saying I have the same problem, what I haven't tried yet is changing the pci-e slot, you can try this.

Oh, right, sorry. So far we have me and you having the same problem, and another user not having it. That's really strange.

But I doubt that changing the PCIe slot would help. For one, if I do that, it would be too close to the graphics card, so it would mean less ventilation space for the graphics card's fans. But the PCIe slot thing would be a good idea if the card wasn't working at all. The card works just fine in Resolve, and Fusion can see the card, since it shows in the preferences, but there are no dot buttons for it. That tells me there's something in Fusion that is not right.

This is very disappointing. A week and a half after final release, and I still can't use Fusion Studio with my Decklink card. Nothing from BMD, no 20.0.1 bug fix release, nothing.

I love it because when the version 20 betas started, it seemed that every few days there was a new beta version. And I installed them but it's not like I really needed a new version. But now that I really hope a new version of Fusion Studio is released and finally fixes this, every day it's the same, final release from May 28th.

Heavy sigh.

I just want to point out that it's been several weeks since Fusion Studio 20 was released in its final version and there's still no solution for this.

I have called several times about this and had email exchanges with no luck, then strangely with Version 20 problem went away. However, this morning I sit down to finish some deadlines and windows had updated overnight. It's back MF! The problem persists even after system restore and clean install of Fusion Studio. Please fix this, I now have to drive home and hope the system there is still working. Been working with Fusion since version 2.5 and it was always rock solid when it was Eyeon!

OK so version 20.0.1 finally fixed this, but with a caveat. If your project is 2K DCI Scope, and I assume other aspect ratios that are not 16:9, you can't use 10 bit YUV because it will chop about 100 pixels from the bottom of your scene. Changing to 10 bit RGB fixes this.

But to me the Decklink output needs to have the same ability to use display LUTs like the viewers. Blender renders in linear, so to view the render like you saw it in Blender, you need to use the OCIO Colorspace effect as the viewer LUT, obviously loading the config.ocio from the current Blender install and setting the same transform that you had in Blender, like AgX High Contrast for example. But the only way to achieve this in the Decklink output is to put the OCIO colorspace as a node after the node you're trying to preview. So if you rendered a multilayer EXR and you "unfold" it to all the passes that you need, like Diffuse, Glossy, etc, if you want to preview the Glossy Color pass for example, you can't just click on it and press 3 to send it to the Decklink card. You need to keep the OCIO Colorspace node and move it around over and over to preview every node that you want, like if you apply a glow to the glossy direct and so on. This is a pain.

I mean, the point of the Decklink card is to be able to preview real Rec.709 and Rec.2020 with HDR, so it seems to me that if the viewers have the ability to have an OCIO colorspace set permanently or at least as permanently as you need, the Decklink output should also have that choice.

And speaking of the OCIO Colorspace LUT for viewers, it's partially broken because if you used AgX Very High Contrast, High Contrast or Medium High Contrast, it looks something like this:

Screenshot 2025-07-02 125113 (Large).png (788.38 KiB) Viewed 1845 times

Everything below those levels shows fine. Maybe this was a bug before and I didn't see it because I usually render to AgX Base Contrast, so I had been using that, but I wanted to see how it looked with other levels.

This bug is only present in the viewer LUT, because if I add a regular OCIO colorspace node in the layout and set it to Very High Contrast, it looks just fine.