Hi there
@Dogbone, welcome to the forums.
Using your world file, I was able to open the world 100% of the time - it just took a loooong time. I opened it 4 times and clocked each time about 35 minutes. Going off of what Neviskio mentioned I figured you had a ton of water somewhere, and, for me, I normally accidentally flood my underworld. So I brought with me a Super Absorbent Sponge and went looking down in your underworld. You had a bunch pooled up on the left hand side and then a huge amount right above the underworld area on the left all the way near the edge of the world.
I mopped it all up, then saved the world. Now when I open the word it opens immediately, so the water on the left was very likely the problem. I’ll attach the newly saved world file here if you wanted to use it. The only changes I made to the world was removing the water on the left, and leaving a handful of gravestones in the underworld (so many Red Devils!). So if you see gravestones with a character name of “Guide” that was me. Oh, a slime rain came and went (I did not kill King Slime), one of the mechs tried to naturally spawn (I did not kill it), and a blood moon came and went. It’s now around 4:30 in the morning.
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