Kdenlive rendering crashes

Doug-Phoenix · January 2, 2026, 2:23pm

Hello,

I have some issues with Kdenlive crashes - this post is about rendering.

System (neofetch)

dw@dw-OptiPlex-5070 
    
OS: Zorin OS 17.3 x86_64 
Host: OptiPlex 5070 
Kernel: 6.8.0-90-generic

Packages: 2488 (dpkg), 55 (flatpak), 6 (snap)
Shell: bash 5.1.16
Resolution: 1920x1080, 1920x1080

DE: GNOME 43.9
WM: Mutter
WM Theme: ZorinBlue-Light
Theme: ZorinBlue-Light [GTK2/3] Icons: ZorinBlue-Light CPU: Intel i7-9700 (8) @ 4.700GHz GPU: Intel CoffeeLake-S GT2 [UHD Graphics 630]
Memory: 14611MiB / 31878MiB

I have a “large” project that is mostly a slideshow with around 500 photos. Photos were exported from a RAW developer (darktable) into .jxl format, and display correctly in kdenlive. There are added audio tracks and basic transition effects (fades mostly).

The project preview plays correctly.

I managed (once) to render the project successfully as MP4-H264/AAC. It is painfully slow (4-5 hours for 52 min video), but I do not have a powerful system (no GPU).

Now I’m trying to use another format WebM-AV1/Opus (libre-dav1d) that I used on a shorter project. (It is more compact). Here with this project, I get errors every time. Below is the error log from trying to render about the first 5 minutes. Do I need to do something with GTK? Anything else?

I have the option to use either Wayland or X11, but behavior is the same with both (using X11 here).

Rendering of /home/dw/Videos/Italy 2025-4kb-Chapter 1.webm crashed

Gtk-Message: 22:03:01.620: Failed to load module “xapp-gtk3-module”
Qt: Session management error: Could not open network socket
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
qt.imageformats.tiff: “Unknown field with tag 50935 (0xc6f7) encountered” qt.imageformats.tiff: “Unknown field with tag 50936 (0xc6f8) encountered” qt.imageformats.tiff: “Unknown field with tag 50940 (0xc6fc) encountered”
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
qt.imageformats.tiff: “Unknown field with tag 50935 (0xc6f7) encountered” qt.imageformats.tiff: “Unknown field with tag 50936 (0xc6f8) encountered” qt.imageformats.tiff: “Unknown field with tag 50940 (0xc6fc) encountered”
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
qt.imageformats.tiff: “Unknown field with tag 50935 (0xc6f7) encountered” qt.imageformats.tiff: “Unknown field with tag 50936 (0xc6f8) encountered” qt.imageformats.tiff: “Unknown field with tag 50940 (0xc6fc) encountered”
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
TIFFReadDirectory: Warning, Unknown field with tag 50935 (0xc6f7) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50936 (0xc6f8) encountered. TIFFReadDirectory: Warning, Unknown field with tag 50940 (0xc6fc) encountered.
qt.imageformats.tiff: “Unknown field with tag 50935 (0xc6f7) encountered”
qt.imageformats.tiff: “Unknown field with tag 50936 (0xc6f8) encountered” qt.imageformats.tiff: “Unknown field with tag 50940 (0xc6fc) encountered”
[libopus @ 0x77946c203c00] Value 33366.000000 for parameter ‘frame_duration’ out of range [2.5 - 120]
Svt[info]: ------------------------------------------- Svt[info]: SVT [version]: SVT-AV1 Encoder Lib v2.2.0 Svt[info]: SVT [build] : GCC 14.3.0 64 bit Svt[info]: -------------------------------------------
Svt[warn]: SVT-AV1 has an integrated mode decision mechanism to handle scene changes and will not insert a key frame at scene changes Svt[warn]: If you are using tiles with the intent of increasing the decoder speed, please also consider using --fast-decode 1, especially if the intended decoder is running with limited multi-threading capabilities.
Svt[info]: Number of logical cores available: 8 Svt[info]: Number of PPCS 148 Svt[info]: [asm level on system : up to avx2] Svt[info]: [asm level selected : up to avx2] Svt[info]: ------------------------------------------- Svt[info]: SVT [config]: main profile tier (auto) level (auto) Svt[info]: SVT [config]: width / height / fps numerator / fps denominator : 5184 / 3888 / 30000 / 1001 Svt[info]: SVT [config]: bit-depth / color format : 8 / YUV420 Svt[info]: SVT [config]: preset / tune / pred struct : 7 / VQ / random access Svt[info]: SVT [config]: gop size / mini-gop size / key-frame type : 150 / 32 / key frame Svt[info]: SVT [config]: BRC mode / rate factor : CRF / 32 Svt[info]: SVT [config]: AQ mode / variance boost strength / octile : 2 / 1 / 7 Svt[info]: -------------------------------------------
[libopus @ 0x77946c202f00] Value 33366.000000 for parameter ‘frame_duration’ out of range [2.5 - 120]

Doug-Phoenix · January 2, 2026, 2:38pm

Sorry, forgot to mention:

Kdenlive 25.12.0 as a flatpack.

Doug-Phoenix · January 5, 2026, 2:32pm

I spent the weekend trying several approaches.

I added timeline zones (“Chapters”) and rendered one at a time. The main problem was toward the end. The last one crashed every time. There were a couple of short video clips (including one from an iPhone), and I made sure to transcode these.

I tried rendering with a number of different presets, including MP4-H264/aac which had worked previously. No luck.

So the problem should lie in one of these cases:

User error. (But everything else renders..)
File corruption. (But the preview plays just fine.)
Inadequate hardware. (My main concern. But it meets the spec per documentation.)
Some unknown bug in the latest release (Then I successfully rendered the project, it was on the previous release.)

Hardware includes an Intel i7-9700 with 8 cores, 32 GB RAM, iGPU …

Some guidance would be appreciated.

Eugen_Mohr · January 6, 2026, 8:05am

Hello @Doug-Phoenix and welcome to the forum.

Please try with the AppImage from the download page to see if there are any flatpack packaging issues.

Doug-Phoenix · January 6, 2026, 1:25pm

Thank you, @Eugen_Mohr

I have success with the AppImage. I noticed that the project loaded more quickly, and I think rendering was faster, too.

I’ll check later for some different crash issues that I noticed while editing. Will report back here is all is good, or I may start another thread if not.

I appreciate your good support.

Eugen_Mohr · January 6, 2026, 2:13pm

Thank you for the feedback. Glad to hear it works with the AppImage.

Doug-Phoenix · January 6, 2026, 9:39pm

I’ve done a little more testing, and crashing issues that I have seen with editing have not occurred with the AppImage. For example, with the flatpack, adding a Bézier curve to a clip would cause Kdenlive to crash, but I am not seeing this with the AppImage.

I am happy with this solution, and of course will stick to the AppImage now.