In-game Model Texture becomes Purple after Blender.

Hello there. I’ll give a short step-by-step story.

-Playing original Neverwinter Nights 2 campagin.
-Wanted companions to use helmets for realism. (Especially to give one character a mask)
-Learned to edit save file to enable such show helmet option via GFFEditor tool.
-Character wearing a mask gets it higher on her head than it should be.

-Installed Blender for the first time to try and fix this.
-Installed a Blender plugin to edit MDB files. (from NWN2 Nexus site).
-Extracted and opened related file after finding it.
-Simply lowered the mask position a little bit via dragging axis in Blender.
-Exported adjusted height file from Blender and put the file into required folder.
-Character’s mask position fixed.
-The texture recieved a purple tint.

Any solution to remove the purple tint from adjusted mask? Is it something that Blender does by default?

With starting to use Blender, my thought opened to many other modding ideas I had for a while, so I’d like to learn more about removing such issue if it appears later. I can explain more about my previous steps if required.