Howdy, I'm making some courtesy bug reports.
I am scanning a lot of portrait collections for errors right now, and I found these:

CHIMERASDAUGHTER_H.tga is not a valid resref
CHIMERASDAUGHTER_L.tga is not a valid resref
CHIMERASDAUGHTER_M.tga is not a valid resref
CHIMERASDAUGHTER_S.tga is not a valid resref
CHIMERASDAUGHTER_T.tga is not a valid resref
DAUGHTEROFNIGHT_H.tga is not a valid resref
DAUGHTEROFNIGHT_L.tga is not a valid resref
DAUGHTEROFNIGHT_M.tga is not a valid resref
DAUGHTEROFNIGHT_S.tga is not a valid resref
DAUGHTEROFNIGHT_T.tga is not a valid resref
F_FEMALEHUMANARCHERH.tga is not a valid resref
F_FEMALEHUMANARCHERL.tga is not a valid resref
F_FEMALEHUMANARCHERM.tga is not a valid resref
F_FEMALEHUMANARCHERS.tga is not a valid resref
F_FEMALEHUMANARCHERT.tga is not a valid resref
M_CROWISHWIZARD_H.tga is not a valid resref
M_CROWISHWIZARD_L.tga is not a valid resref
M_CROWISHWIZARD_M.tga is not a valid resref
M_CROWISHWIZARD_S.tga is not a valid resref
M_CROWISHWIZARD_T.tga is not a valid resref
M_WISEMALEWIZARD_H.tga is not a valid resref
M_WISEMALEWIZARD_L.tga is not a valid resref
M_WISEMALEWIZARD_M.tga is not a valid resref
M_WISEMALEWIZARD_S.tga is not a valid resref
M_WISEMALEWIZARD_T.tga is not a valid resref
PO_HU_M_OARCHER_H.tga is not a valid resref
PO_HU_M_OARCHER_L.tga is not a valid resref
PO_HU_M_OARCHER_M.tga is not a valid resref
PO_HU_M_OARCHER_S.tga is not a valid resref
PO_HU_M_OARCHER_T.tga is not a valid resref
STALKINGDARKNESS_H.tga is not a valid resref
STALKINGDARKNESS_L.tga is not a valid resref
STALKINGDARKNESS_M.tga is not a valid resref
STALKINGDARKNESS_S.tga is not a valid resref
STALKINGDARKNESS_T.tga is not a valid resref

The longer file names need to be shortened down to 16 characters so that they can be selected and read by the Resource Manager.

It's also a good idea in NWN in general to lowercaps all custom content files so that they don't end up being accidentally duplicated in the same hak, however, since these are portraits, that is less of an issue unless someone put together a portraits hak for your server. (To be able to read the files without being able to select them, but without the /portraits clutter)

Cheers!