3D FFT Denoiser parameters changed in FFMPEG
See this commit: https://github.com/FFmpeg/FFmpeg/commit/126d5d3b5fa7916a0df8edc6ca44316d60a70ad8
The block size parameter changed from 2^N to N. For example, any old files specifying block=4 need to be changed to block=16 (2**4). Not sure if there's a way to do ffmpeg version detection at runtime to make this work.
The currently shipping versions of Kdenlive 22.08.x seem to not be affected yet.