Because you need to put the addon in D: directory, and all assets should call the textures from there.

(If you do not have a D: drive, please feel free to contact and we ajust a solution for your drive.)

1 - Extract the file ARMBWOODS.zip to D: 

----This is essential for the script works, because the textures are all with the path of the "maps" folder  (D:\ARMBWOODS\maps), if you put the ARMBWOODS folder in a wrong place, the textures would be missing, and the objects become pink (an issue thanks to wrong path).----

2 - Install the ARMBWOODS.zip at Blender without unzip the file.

3 - Enjoy!