5) Open it with Notepad or Notepad++ (Either works). There should be at least 1 line of code, player_manager.AddValidModel, and also probably list.Set. You do NOT need anything else. All you have to do is clean up all code that is in there and add this:

player_manager.AddValidModel( "Skytrooper General", "models/omo/skytroopergeneral/skytroopergeneral.mdl" );
list.Set( "PlayerOptionsModel", "Skytrooper General", "models/omo/skytroopergeneral/skytroopergeneral.mdl" );

6) Place the extracted Skytrooper addon on garrysmod\addons folder (On the Steam library, you can right-click on Garry's Mod, then select "Manage", then click on "Browse Local Files").

7) The model should now properly be selectable on the Playermodels window. Have fun!

So, apparently, the lua code necessary to make the playermodel work is missing. Here's a quick fix:

1) Either you extract the .gma addon file OR download it from Steam Workshop Downloader already extracted.

2) In the addon folder (Where's the "models" and "materials" folders), create a new folder named "lua".

3) In the "lua" file you just created, create a new folder named "autorun".

4)Extract any other playermodel addon, go to their "lua" folder, then the "autorun" folder. You will find a .lua file. Copy and paste it in the Skytrooper General's autorun folder.

How can I equip this model? It's nowhere in the Playermodel list.

Hey Brother, im an Administrator from a German Server, and I was wondering if we could use your Addon on our Server! Would be much appreciated!

Yeah just give me credit idc

Hi there! I am interested in turning your model into an NPC to add it to this pack:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1798541255

Do I have your permission to do so? I think it would be a nice addition to it.

Is this a playermodel, or is it usable using !model?