Travel Optics is a mod that adds Intergrated Content for Alex's Caves, Cataclysm, and Iron's Spells N' Spellbooks. In March, Cataclysm 3.17+ had some changes that made T.O + Magic N' Extras not work with it. GameTechBC said they would try to resolve the problem but for now to downgrade to Cataclysm 3.16

That has been the solution but recently, Mcl_Ender has archived/deleted the older versions of Lionfish API. Because Cataclysm 3.16 uses the older versions of Lionfish which Mcl_Ender has deleted and there is no way to get them unless someone who had Lionfish API in a pack. didn't update it yet. I haven't updated one of my modpacks in a while and I don't plan to for a bit. I later found out using Travel Optics with Cataclysm 3.16 has the 3D models for Cataclysm gone and the recipes gone. It isn't because of Travel Optics but because Travel Optics needs 3.16 but 3.16 needs the older version of Lionfish which is gone.

I decided to move the older mod version's jar into a modpack with just Travel Optics, alex's caves, spells and spellbooks and Cataclysm 3.16 and Lionfish API 2.4. Do not update Cataclysm or Lionfish AT ALL. Feel free to just copy the jar file or use the modpack as a Template for your packs.

These are the mods you can go check.

L_Ender 's Cataclysm - Minecraft Mods - CurseForge

Lionfish API - Minecraft Mods - CurseForge

T.O Magic 'n Extras - Iron's Spells Addon - Minecraft Mods - CurseForge

GameTechBC’s Author Page - Curseforge