Importing Mdx Special Effects

How do to use imported Mdx effects? I tried following the tutorial for the unit model mdxes but i got a fatal error.

same as regular models, if you got a fatal error then you have a bad model most likely.

When you select it as a custom path/type the path name, make sure it ends in .mdl; WCIII automatically converts a .mdx .mdl after it's imported.