If any vertice of a mesh has more than 3 weight links (is rigged to more than 3 bones), Blender Source Tools will either tell you "too many weight links, you can't compile this model" or "too many weight links, I'll just cull it down to 3 for you" depending on the "weight link cull threshold" in the Source export properties, of which you are getting the second message. As long as you keep a Blender session of it, you should be fine.

Try going to Edit Mode with the mesh that breaks when exporting, select all vertices, and press Shading > Smooth Vertices (or such) in the left panel, then export again. If I remember right, that fixed it for me last time I had this problem.

Additionally, try enabling "Auto Smooth" on the mesh. I found that doing that would also make the same error show up in Blender.

Yeah, it's a default setting in Source FilmMaker. Don't worry, everyone just uses the eye flexes instead of moving the viewTarget. (At least I do.)

引用自 xDShot™：

引用自 Zappy：

You mean that thing Source does automatically when using eye shaders?

I mean scale uv map of eyes longer/shorter along latitude.

You mean that thing Source STILL does automatically when using eye shaders?

Source "projects" the UV map of eyes in run-time, ignoring how the UV co-ordinates of the model itself look like.

引用自 xDShot™：

I think tweaking eyes' uv-map will help.

You mean that thing Source does automatically when using eye shaders?

I guess so too. *Shrug*

I mean make them extend more out of the head, like, less flat or something.

Try adding $ParallaxStrength 0 to the materials.

Well, then try making the eyes bumpier.

Also, what eye shader are you using?

Try putting the eye locations (both in $Model and the eye attachment) a bit further back into the head.

引用自 Афганский бульон：

I just cant decompile vmdl to mdl.

Neither can anyone else. Not straight from VALVe Models to Source Models, nor from VALVe Models to StudioModel Data or Data eXchange Model to Source Models.