On starting a new game in Morrowind it gives the message 

Model Load Error: Meshes\tr\b\TR_pb_IMP_head03.nif
cannot load file in Meshes\tr\b\TR_pb_IMP_head03.nif.
Will use the default object Marker_Error.NIF.
Model Load Error: Meshes\TR\a\TR_a_Netch_M_cuirass3.nif
cannot load file in Meshes\TR\a\TR_a_Netch_M_cuirass3.nif.
Will use the default object Marker_Error.NIF.
Render Creation Error: ""

I read elsewhere that this was likely an error with the bsa registration but my morrowind.ini appeared to be correct.

[Archives]
Archive 0=Tribunal.bsa
Archive 1=Bloodmoon.bsa
Archive 2=PT_Data.bsa
Archive 3=TR_Data.bsa

[Game Files]
GameFile0=Bloodmoon.esm
GameFile1=Morrowind.esm
GameFile2=Tamriel_Data.esm
GameFile3=Tribunal.esm
GameFile4=TR_Mainland.esm
GameFile5=TR_Factions.esp
GameFile6=TR_Travels.esp
GameFile7=XE Sky Variations.esp