Originally Posted by Neox
env never really worked for me, try skin or die, it saves all the weights not the envelopes
Env files save vertex weights if the vertices have been baked/adjusted by hand. For verts that are just 'enveloped' and haven't been adjusted by hand, their vert weight is not saved out (it is, on the target mesh, affected by envelopes again). The bone envelopes are also saved and loaded but this is mostly useless for games. If you are having problems transferring vert weights, it is because your verts are not baked- either bake them, or you can select your verts, give them some weight to a bone, then remove it- that is like hand-adjusting all of them and will remove envelope influence.