It worked for a bit but now every time I try to open up the world, the game crashes, I've tried both allocating more ram and increasing the "MaxPermSize" and it stopped saying "shutting down the internal server" but it still crashes.
MCEternal is a 1.12.2 modpack so the 1.13 tag is confusing me, did you backup your world before this started happening? What happened before or when it started crashing?
The issue seems to be NBT but I don't know what for, did you change an item or something and it's crashing or is it that the world isn't loading it correctly which I'm assuming is more so the case.
I'd suggest using a backup of your world if you have one or starting a fresh world to see if the modpack is having issues and it's not just the one world your using. Otherwise ask the creator to see.
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