First of all- I know how to work structure blocks. The whole save thing, etc. But I heard that you can copy them between worlds, and I can't figure out how to do that, and I haven't found a youtube video on it. I have a tree on a creative world which I'm trying to copy over to a server, but it's just not working.
I've been getting the message: Structure "Tree" is not available
It is really easy, at least if you are using windows. Go to the search bar at the bottom of your screen, type in the windows search bar %appdata% and click on the folder that appears. From there you click on the .minecraft folder, and in that folder open up the 'saves' folder. You should now see all your worlds, at least in single player, I do not know if servers are saved there. Open up the world with the structure block save you need, and you will see a folder called 'structures'. That folder has all the files that structure blocks have saved. You can then copy that folder, and move it to any other world, as long as you put it in the proper place. (.minecraft<saves<any world folder). I have done this a couple times and it has never messed up anything. Hope my instructions were helpful ^^.