The screen is black
Connected and paired, but the phone shows nothing. Playback state, the transmit-paused pill, and the 4K HEVC failure on Windows.
The phone says it is connected but the picture is black, or frozen on an old frame.
Work down in order — the first two checks take seconds, and the third is a real product bug with a workaround you need to know about.
1. Nothing is being rendered
Mercury Transmit is a push interface. Premiere Pro hands the plugin a frame when it renders one and at no other time. It does not poll, and the plugin cannot ask for a frame.
That means a paused playhead on a sequence that has not changed produces no frames at all. The plugin keeps a copy of the last frame it received and replays it to a phone that connects, so a parked playhead usually still shows the right picture — but if the plugin has never seen a frame since Premiere Pro started, there is nothing to replay and the phone stays black.
Press Space in Premiere Pro, or scrub the playhead. If a picture appears, this was the cause and nothing is wrong.
After about 1.6 seconds with no decoded frame the app replaces the black screen with Connected to Premiere and Waiting for video — open or play a comp/sequence in Premiere, plus a Still nothing? Open the setup guide link.
This is also the normal state for After Effects with no composition previewing. After Effects only pushes frames while a preview is actually running.
2. Premiere Pro stopped transmitting
If the phone shows a picture with a pill across the top reading Premiere isn't sending frames, the plugin has told the app that no Transmit instance is live any more. The picture you are looking at is the last frame that arrived.
The pill sits above the HUD and survives the auto-hide, so it stays visible after the controls fade. Tap it to open the walkthrough.
The usual causes, in order:
The last sequence was closed. Open one.
PreviewMonitor was unticked in Preferences → Playback. Re-tick Video Stream under Video Device.
Disable video output when in the background was checked. Uncheck it — otherwise Premiere Pro stops the moment it loses focus, which is exactly when you are looking at the phone.
Video Stream ticked and Disable video output when in the background unchecked is the configuration this pill is asking for.
3. Windows: 4K HEVC fails silently
This is a known bug, not a misconfiguration. On Windows, a 4K sequence encoded as HEVC can fail with no error on either side — Premiere Pro shows the device ticked, the phone shows connected and paired, and the screen stays black.
Do these all apply to you?
All four conditions must hold for this to be your problem:
| Condition | Value |
|---|---|
| Host | Windows, with an NVIDIA or Intel GPU |
| Codec | H.265 (the default) |
| Resolution Limit | Source or 2160p, on a 4K sequence |
| Setup window toggle | Use NVIDIA / Intel HW HEVC encoder switched off (the default) |
The default Resolution Limit of 720p never trips this, because it encodes at 1280×720. Free-tier users are capped at 360p on the short side and cannot reach it either. It only affects Pro users who reach for maximum quality on a 4K timeline.
Why it happens
NVIDIA and Intel expose hardware HEVC only as an asynchronous Media Foundation transform. With Use NVIDIA / Intel HW HEVC encoder off, the plugin skips every asynchronous transform, so hardware HEVC becomes unavailable and it falls through to Microsoft's software HEVC encoder.
The plugin then refuses software HEVC above 6 megapixels on purpose. At 4K that encoder blocks Premiere Pro's video thread past the host's own watchdog and Premiere Pro is killed with no crash dump — a measured 2160×3840 deadlock against a clean 1620×2880. Refusing to encode is the lesser failure, but the refusal currently has no way to reach the phone, so it arrives as silence.
Three ways to fix it
Any one of these is enough. They are listed cheapest-first.
Lower the Resolution Limit. Tap the resolution chip in the live view's HUD — the round button showing the current value, left of the gear — and pick 1080p. Anything at or below 1080p is well under the 6-megapixel ceiling. This is instant and needs no restart.
Switch the codec to H.264. Open the gear, and under Encoding set Codec to H.264. The software H.264 encoder is exempt from the ceiling because it is a well-behaved synchronous transform, so 4K works.
Turn the toggle on. In the Setup window's DEVICE card, switch Use NVIDIA / Intel HW HEVC encoder on. This gives you real hardware HEVC at 4K. It is off by default because asynchronous transforms were historically unstable on some drivers, so treat it as opt-in and watch for instability.
720p is marked Recommended; Source and 2160p are the two rungs that trip the bug on a 4K sequence.
Use NVIDIA / Intel HW HEVC encoder sits directly below Discoverable on network in the DEVICE card. It is not behind Advanced info.
The Resolution Limit control lives on the HUD chip in the live view, not in the settings panel. See Encoding settings.
Confirm it from the log
This bug leaves a distinctive trail in %LOCALAPPDATA%\PremiereLive\plugin.log.
Run each of these from a Command Prompt — findstr treats brackets as a
character class, so the /C: flag is required for a literal match:
findstr /C:"Refusing" "%LOCALAPPDATA%\PremiereLive\plugin.log"
findstr /C:"encoder Configure failed" "%LOCALAPPDATA%\PremiereLive\plugin.log"The two lines that identify it:
Refusing 3840x2160 on SW HEVC MFT "..." — above 6.0 MPx cap (HW HEVC unavailable: async MFTs not yet supported)
encoder Configure failed (3840x2160 @ 30 fps) — Ready() stays false, retry on next frameThe second line repeats once per frame for as long as the sequence plays.
You will also see the upstream cause, at INFO level:
async MFT — skipping (Setup → "Use NVIDIA/Intel HW HEVC encoders" is OFF)If none of these appear, the black screen is something else — go back to checks 1 and 2, or continue at It connects but nothing happens.
4. The picture is there but looks wrong
A picture that arrives but reads as too dark, too flat, or shows transparency as black is not a failure — see The colors look wrong and Picture and color.
Last updated on
It connects but nothing happens
The phone finds the computer and pairs, then sits there. Firewall rules, background output and a missing restart are the usual causes.
The stream stutters or lags
Stuttering, tearing or delay on the phone. Read the stats HUD, then fix the Wi-Fi, the resolution or the GOP mode.