lav + ffdshow (raw video processor not working in wmp)

anyone know why lav refuses to load with the ffdshow raw video processor when using wmp? it's handy for using the processor for aspect ratio changing when using wmp but for some reason it refuses to load, only the audio processor works. i played with the merits but nothing making it load with lav.

if i use a third party splitter i can use ffdshow just fine.

just to note i use vlc and mpv but wmp is also nice to use sometimes.

in mpc hc and be lav and video processor work fine but are redundant because those players have built in aspect ratio settings.