There are missing textures on both sides of the archway behind the railgun, and a large square missing texture directly underneath the shotgun. Console dump -

trying textures/gothic_door/skull_door_b.TGA...
trying textures/liquids/proto_grueldark2.TGA...
WARNING: R_FindImageFile could not find 'textures/liquids/proto_grueldark2.tga' in shader 'textures/gothic_floor/q1metal7_99spot'
Shader textures/gothic_floor/q1metal7_99spot has a stage with no image
trying textures/gothic_door/skull_door_a.TGA...
trying textures/gothic_door/skull_door_c.TGA...
trying textures/gothic_door/skull_door_f.TGA...
trying textures/gothic_door/skull_door_e.TGA...
trying textures/gothic_door/skull_door_d.TGA...