I dont crash or anything no issues posted to files just can't get the dragon to respawn. i'm using the expensive crystal recipe that uses nether stars to craft but once place nothing happens. no beams of light no sounds nothing. just they sit there. all 4 one on each side.

Minecraft 1.12
DE 1.12-2.3.3.261

@Wrsaith Screenshot of your placement? Are you using just DE or some other mods or a modpack?

I am using several mods but DE is the only one that effects the dragon to my knowledge. as stated in the wiki i've got one crystal in the middle of each side. on all 4 sides. i have tried the corners, the edges of the sides and every combination of each. I've even turned off the expensive mode for the crystals and tried again with the same outcome.

i've checked through all my other mods and the dont have any config concerning the dragon other than like immersive engineering where they have the dragons breath cartridges for the gun.

I updated the mod to your latest release for 1.12 but still nothing as well.

As an update I deleted the end world and let it respawn killed the dragon again and it worked fine. So maybe something with how it gen'd the first time messed it up. But also even tho DE was changing the recipe one of my friends was still able to make the end crystals the default way, Tho not sure if he was just being delusional xD

That has nothing todo DE. DE only changes the recipe and does not affect the ritual in any way. I suspect there was some sort of world gen issue or something maby related to transferring a world between versions? No idea but its not DE.