Hi !

Since this afternoon (sunday 30 May 2021), we keep running into this error message when we try to render any video :
https://i.imgur.com/1cohTXW.png (image is too wide for the forum, it exceeds the 720px limit)
Edit : error message is

Rendering of file.mp4 crashed

mlt_repository_init: failed to dlopen /app/lib/mlt/libmltjack.so (/app/lib/mlt/libmltjack.so: undefined symbol: filter_jackrack_init)
[mp4 @ 0x7fafbc200f40] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead. [mp4 @ 0x7fafbc200f40] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.

We had no trouble working yesterday. The problems started occurring at the same time today (around 4pm CET) on our 3 computers, while we did not update anything on our side.

Environment is :

• Kubuntu or Lubuntu 20.04
• Kdenlive 21.07.10 installed via flatpack (nightly build) - we had trouble with the "stable" version, it kept crashing at startup when we were using a generated countdown
• MST 6.26.1
• Latest proprietary nvidia drivers

I can provide any log needed, as long as you tell me how th get them (I have 0 experience working with flatpak and snaps, and for the love of myself do I absolutely hate them).

I tried a flatpak update, it updated a bunch of stuff, but kdenlive and MLT version stayed the same and the crash still occurs.

Any help appreciated

Next steps :

I tried reverting to Kdenlive stable, but the project couldn't be opened anymore (error message saying to update kdenlive).

Tried to generate a script and render from command line with melt : segfault

Updated to Ubuntu 20.10 : same error message, but at least rendering in a terminal via melt works.

As far as I understand, the error message we get means a lib is missing from the flatpak (since path begins with /app/lib).
The person/script who packages the flatpak broke the nightly release it seems.

Have you tried the appimage versions? Current release and nightly built? That would eliminate the packaging issue.

berndmj wrote:Have you tried the appimage versions? Current release and nightly built? That would eliminate the packaging issue.

AppImage and stable cannot open a project created with Nightly ( get a message asking me to update my version of kdenlive).

I tried completely removing kdenlive, and install it from the different flatpak sources, but noon of them works.

barthvr wrote:I tried completely removing kdenlive, and install it from the different flatpak sources, but noon of them works.

Don't install from any source, flatpack or not. Just download the appimage from the official kdenlive.org web site, make it executable and run it (I put the appimage files into /opt/kdenlive and create a .desktop file for easy access).
As far as the error is concerned when opening your project I am afraid I cannot help you.
Right now there are several issue with any packaged version of kdenlive so again I recommend to use the appimage.
Hope this helps