can not finalize / iris colors does not have any image data

[DENG-XC]

Hi, thank you for your hard work to make this add on. this is a great human generate add on, but I have problem when I use this add on.

When I finalize the model, it pop up error message said iris colors does not have any image data.

Blender version: 4.0.2
MB-lab version: 1.8

Python: Traceback (most recent call last):
File "C:\Users\DENG_XC\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\MB-Lab-master_init_.py", line 1712, in execute
mblab_humanoid.save_all_textures(self.filepath)
File "C:\Users\DENG_XC\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\MB-Lab-master\humanoid.py", line 532, in save_all_textures
self.mat_engine.save_texture(new_filepath, target)
File "C:\Users\DENG_XC\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\MB-Lab-master\materialengine.py", line 339, in save_texture
file_ops.save_image(img_name, filepath)
File "C:\Users\DENG_XC\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\MB-Lab-master\file_ops.py", line 394, in save_image
img.save_render(filepath)
RuntimeError: Error: Image 'iris_color.png' does not have any image data