Which would still be wrong, this is a VFXFOGVOLUMEINFO_FILE, which isn’t part of a data file mounter, but is in gta5.meta so can be loaded using a replacement world meta file.
A .ymt file is technically a meta file, and to stream meta files to the client you have to declare a data_file type in the resource manifest. Only the types from this list will work, others wont, meaning you can’t stream the “vfxfogvolumeinfo.ymt” file.
Like deterministic_bubble said, it is in gta5.meta, which you can find by searching gta5.meta in OpenIV. Right-click it, select “Save content/Export…” and save it anywhere. Then open it with any text-editor and remove the part where it says “vfxfogvolumeinfo” like so:
After that, put the “gta5.meta” file into it’s own resource, and add this to the “fxmanifest.lua” file:
replace_level_meta "gta5"
files {
"gta5.meta"
}
Note: Some of this might be explained wrong, but I got it to work on my test server.