TileEntity

Maybe starcatcher

new log?

Maybe an issue with supplementaries in connection with JEI or allthetrims Make a test without supplementaries or allthetrims

Forge requires Forge mods to work, NeoForge is not the same

Embeddium is by default not compatible with Veil

Hm I have no idea

Yes If Create gets an update, most of the addons have to update, too

They do work together - but not all builds are compatible

The latest Create build may not work with Create Aeronautics

Use this as working base and just add some mods

Does this modpack work? https://www.curseforge.com/minecraft/modpacks/distant-horizons-iris-shaders

Delete the config files of these 2 mods (config folder) - if there is no change, use a pre-configured mod pack with these 2 as working base

Does it work with only these 2 mods, without an other mods? If yes, add the rest of your mods one by one or in groups

Check for updates of these 2 mods - maybe there are newer 1.21.1 builds of these

Try other builds of these 2 mods

Maybe some sodium addons (sodium options api etc)

Does it work without Iris?

Remove iceberg, Toggle Enchantments, Legendary Tooltips and Quark

There is another - letsdo-bakery requires doAPI Also add this mod: https://www.curseforge.com/minecraft/mc-mods/do-api If this is still not working, add the new crash-report

The link to the log is wrong

lootintegrations_iceandfire requires lootintegrations Add this mod: https://www.curseforge.com/minecraft/mc-mods/loot-integrations

Make a test without survivalisland

Add the crash-report or latest.log (logs-folder) with sites like https://mclo.gs/ and paste the link to it here

Also remove Biomes We've Gone and add the new crash-report

Does it work without terrablender?