Exporting DFF files with DragonDFF, but getting error message?

So, when I try to export DFF files with Blender, I get this error message, despite having DragonDFF added to Blender. Any ideas what’s going on? I’m completely new to Blender, and have absolutely no clue what I’m doing.

Python: Traceback (most recent call last):
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\gui\dff_ot.py”, line 134, in execute
dff_exporter.export_dff(
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\ops\dff_exporter.py”, line 993, in export_dff
dff_exporter.export_dff(options[‘file_name’])
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\ops\dff_exporter.py”, line 980, in export_dff
self.export_objects(objects)
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\ops\dff_exporter.py”, line 912, in export_objects
self.populate_atomic(obj)
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\ops\dff_exporter.py”, line 756, in populate_atomic
self.populate_geometry_with_mesh_data (obj, geometry)
File “C:\Users\Owner\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\DragonFF-master\ops\dff_exporter.py”, line 627, in populate_geometry_with_mesh_data
mesh.calc_normals()
AttributeError: ‘Mesh’ object has no attribute ‘calc_normals’. Did you mean: ‘flip_normals’?

Do you have the latest release? They say that Cal_normals was removed for Blender 4.0 in last week’s release…

Also, some of the recommendations are to use an older version of Blender…
Perhaps 3.5 would work better…