I get the same problem with MayaLT 2016.5. It seems hairworks needs a 3rd party hair and fur plugin capable of creating specific Guide hairs. Curve creation alone don’t seem to work in MayaLT.
But why support MayaLT with a plugin if there is no such hair and fur plugins available for MayaLT under Mel Scripts.
I have followed everything within the documentation below which suggests curves should work under certain conditions, which I believe, have been met.
Have you solved this problem?