On Sat, 08 Nov 2025 09:25:18 +0100,
Walter Alejandro Iglesias <wai@roquesor.com> wrote:
> 
> Hello,
> 
> Blender crashes always I run "render animation" to a ffmpeg video.  (It
> has no problems when rendering to a image sequence).
> 
> Using latest snapshot.
> 
> 
> Thread 2 received signal SIGILL, Illegal instruction.
> [Switching to thread 232396 of process 54210]
> 0x00000956337d3160 in ff_rgbaToY_avx2 () from /usr/local/lib/libswscale.so.9.0

This smeels like your CPU doesn't support AVX2, but ffmpeg tries to use it.

Can you share your CPU?

-- 
wbr, Kirill