Need help with mirillis action screen recording

[edwardbellin]

Hello,

I'm experiencing an issue with Mirillis Action v4.45 during screen recording. I typically use MP4 format with 360 FPS, as it has always provided the best results. However, yesterday, I started recording and found that when I tried to play back the video, it was unplayable.

It appears the recording has stopped; the thumbnail is missing, and while it shows that recording occurred, I can’t access the video. Additionally, hardware acceleration is now unavailable, though I believe it was functional before.

When I switched from 360 to 144 FPS, recording resumed, but the playback was filled with severe lag.

I really need assistance with this issue. I've used this software for years without any problems, and I'm not sure how to resolve this! Thank you!

[EmilyhNqpe]

It sounds like something changed at the system or driver level rather than Action itself. Recording MP4 at 360 FPS is extremely demanding, and if hardware acceleration suddenly became unavailable, that would explain the corrupted files and missing thumbnails. First thing to check is your NVIDIA driver—make sure it’s up to date and that NVENC is enabled in both the driver panel and Action settings. Also verify Windows updates or any recent codec installs. If hardware acceleration isn’t restored, high-FPS MP4 recordings will struggle or fail. Reinstalling Action and resetting settings can also help rule out a config issue.

[haroldbishop]

Recording at 360 FPS is extremely demanding. If hardware acceleration (GPU encoding) is no longer available, the software may be trying to encode via CPU only — which can corrupt files or make them unplayable. That would also explain the missing thumbnail and broken playback.

[Friest]

Sorry to hear you're experiencing this issue. It sounds like there may be a problem with the codec or hardware acceleration after a recent update. I recommend checking for the latest graphics driver updates and reinstalling Mirillis Action to restore default settings. You might also try lowering the FPS and testing different recording formats to see if the issue persists.

[kentwoodard]

A few things to try:

• Check GPU drivers – If hardware acceleration suddenly became unavailable, it’s often driver-related. Try reinstalling or rolling back your GPU driver.
  Verify encoder settings – Make sure the correct hardware encoder (NVENC / AMD / Intel) is selected in Action. If it falls back to software encoding, 360 FPS will likely fail.
  Check disk write speed – Recording 360 FPS MP4 generates massive data throughput. If your drive is nearly full or slowing down, files can become corrupted or incomplete.
  Test lower but stable FPS – Try 120 or 240 FPS instead of 144 and see if playback improves.
  Repair/reinstall Action – Sometimes updates break codec components.

The missing thumbnail and unplayable file suggest the recording didn’t finalize properly (file header not written), which often happens if the encoder crashes mid-recording.

[reindeer21]

Thanks for the suggestions. You might be right about something changing at the driver level. I checked and noticed my NVIDIA driver was actually a few versions behind, so I updated it and made sure NVENC is enabled again in Action.

[violagoodman]

It sounds like the issue may be related to the very high 360 FPS setting or a hardware acceleration problem after the update. You could try updating or reinstalling your GPU drivers and resetting Action’s recording settings to default. If the problem started with v4.45, testing an older stable version might also help confirm whether it’s a version-related bug.

[brianallen]

This usually happens when hardware acceleration (NVENC) stops working. When that breaks, Action switches to CPU recording → which can’t handle 360 FPS → results in broken or laggy videos.

Try this:

Reinstall/update your NVIDIA driver (very important, do a clean install if you can)
Open Action and check if GPU/NVENC comes back
Don’t use 360 FPS for now — test with 60 or 120 FPS first

Also make sure you’re recording to an SSD with enough space, slow drives can mess up recordings too.

Once NVENC is back, your recordings should be normal again

[exactthat]

Hello,

I'm experiencing an issue with Mirillis Action v4.45 during screen recording. I typically use MP4 format with 360 FPS, as it has always provided the best results. However, yesterday, I started recording and found that when I tried to play back the video, it was unplayable.

It appears the recording has stopped; the thumbnail is missing, and while it shows that recording occurred, I can’t access the video. Additionally, hardware acceleration is now unavailable, though I believe it was functional before.

When I switched from 360 to 144 FPS, recording resumed, but the playback was filled with severe lag.

I really need assistance with this issue. I've used this software for years without any problems, and I'm not sure how to resolve this! Thank you!

It might be related to a recent driver or codec issue—try updating your GPU drivers and reinstalling Mirillis Action! to restore hardware acceleration. Also, 360 FPS is extremely demanding, so lowering it slightly (e.g., 120–144 FPS) and checking disk write speed could help stabilize your recordings.