[HELP] 264 is too small

[Selur]

Okay, there should be some error popups in that case.
-> What do they say? (Alternatively create a debug output level 9 when you press the Avisynth preview)
(Also as a side note: In case your content is not SD but HD or above I would recommend to use Vapoursynth and SVP and not Avisynth.)

Cu Selur