Yup . . . I did a ton of work to set up my spawn point so it would have a portal using Minecraft structure blocks and even added some extra mods to make the blocks something players couldn't screw up. . . and then I ran the code and started a new game.

The exact same structure that was working when I exported it comes back as an invalid build.

The only difference between the working portal and the one that won't work here is that one was spawned in by Recurrent Complex as part of a spawning platform for new players while the other one was entirely placed by me right next to it.

It really is exactly that silly. I'm just glad I didn't use recurrent complex to spawn in an entire system of connected portals between the different worlds of my pack BEFORE I tested to make sure the multiblock spawned in without any errors because this is probably the granddaddy of all spawn platform bugs! lol