Please help with exporting meshes.

I’m trying to export meshes into .nif files and all I’m getting are error messages. Can anyone help me?

Blender NIF Scripts 2.2.2 (running on Blender 245, PyFFI 0.7.2)
Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender\.blender\scripts\bpymodules\
nif_common.py", line 590, in guiButtonEvent
    self.guiExit()
  File "C:\Program Files\Blender Foundation\Blender\.blender\scripts\bpymodules\
nif_common.py", line 752, in guiExit
    self.callback(**self.config)
  File "<string>", line 2516, in config_callback
  File "<string>", line 313, in __init__
  File "<string>", line 577, in exportNode
  File "<string>", line 1327, in exportTriShapes
UnboundLocalError: local variable 'mesh_hastexeff' referenced before assignment