its not working for me
but i can fix it my own (edit vmf)
like this

at first

"LightmappedGeneric"
{
"$basetexture" "signs/stencil001"
"$decal" 1
"$decalscale" 0.25
"$translucent" 1
"%keywords" "tf, frontline"
}

to this

"LightmappedGeneric"
{
"$basetexture" "signs/stencil001"
"$decal" "1"
"$decalscale" "0.25"
"$translucent" "1"
"%keywords" "tf, frontline"
}