heavy+medic combo pop it taunt!
I want a Sentry Knockback one so bad

Having trouble with a spray, I'm trying to use an animated one but it won't import
It's a 128x128, 204KB .vtf file placed in the Steam\steamapps\common\team fortress 2\tf\materials\vgui\logos folder with a corresponding .vmt in the ui folder, just as it should be
However it doesn't show up in the drop-down list and when I attempt to import it I can find the file just fine, but selecting it and clicking "Open" does absolutely nothing except close the file browser and bring me back to the Multiplayer Options screen with my previous spray selected and no error messages whatsoever
Any ideas? Google was absolutely no help as every other person having this problem had incorrect spray parameters, and as far as I know they're currently 512x512 and 512KB which I'm clearly under