Hey there, sorry you can't get this working! Do you have any DLC installed? Could be you miss the builders kit. I don't think i used it for this design, but that's a posibility.
Otherwise you do have to have the ship size be unlocked in a current *new* game after you get the download.

How do i go about getting this in game? i go ship design, new design, downloaded. am i doing something wrong? i am playing as the terran alliance i have tryed to find the designs in both a new game and a old save with a good chunk or research unlocked. i have been having the same problem with every ship mod i download.

Hi MadGAD! Please feel free to use the ship model, change it, make it better, make it your own, repost it. It's all good for the community, but thank you kindly for asking :)

Hello! I use your model for a quite a long time, but when BFG:A game comes out, i decide to remodel your unit. Could I get your permission to post slightly changed model for a Cobra\Widowmaker Escort ship?

Thank you @bhowns!

best tiny ship i seen