In the JAPack's entity defintions, i.e. Base/Scripts/mp_entities.def and sp_entities.def, some of the model paths are off. A couple have a leading / (a matter of replacing "/ with ") and saber is typoed as sabre in the weapon_saber entity. (i.e. it should be models/weapons2/saber/saber_w.md3)
Removed 21 instances of the leading "/". No word "sabre" found in either .def files, someone else must have fixed the typo before.
Download revised .def files here:
Obsi said close it.