Decklink 4K Mini Monitor - No 4K Preview in Flame 2026.2.1 (Rocky Linux 9.5)

[memory02]

Hi everyone,

I’m having an issue getting a 4K preview signal out of Flame, and I’m hoping someone here has encountered this before.

The Problem:
My Decklink 4K Mini Monitor works perfectly for FHD (1920x1080 @ 23.97~30p) previews. However, when I switch to 4K-UHD (3840x2160 @ 23.98~30p) in Flame, the preview monitor goes black/no signal.

The Twist:
The hardware seems fine because Blackmagic Media Express displays the 4K-UHD signal perfectly on the same monitor. The issue seems specific to Flame.

My Setup:

• OS: Rocky Linux 9.5

• Flame Version: 2026.2.1

• DKU: 20.2.0

• Video IO: Decklink 4K Mini Monitor (Desktop Video v15.1)

• Connection: HDMI 2.0 cable to a 27-inch 4K-UHD 10bit Monitor (3840x2160 @ 60Hz supported)

I’ve verified the Project Settings and Broadcast Monitor settings in Flame, but only FHD seems to trigger the output. Does anyone know if there’s a specific config file tweak or a known compatibility issue with this driver/DKU combination on Rocky 9.5?

Any help would be greatly appreciated!

[hBomb42]

In the Setup utility page with the list of all the resolutions that you check to enable (embedded 3rd in your post), at the bottom there is a Preview Device popup. Yours is set to Aja when it should probably be BMD. I had the same issue setting up BMD video on a Mac for the first time last month, and @ManChicken was kind enough to point this out to me repeatedly over on Discord.