Ok I think i figured out the causes ..? It doesn't lag in the normal worlds, only in my modified version of Braduhsley's Colossus world and it seems to happen most often when I try to go into one of the 2 new locations I added.
Unsure how I broke it or how to fix it but it seems to be the cause of the lag and error messages. (I'm on mobile if that helps)
Before it kept crashing i had just fixed a problem with my personal entities not spawning by checking the boxes in the location tab on the main locations. I then added 2 new areas so that the location menu could scroll allowing me to choose the location. I added full descriptions using Braduhsley's as guides and made sure to spellcheck everything.
(A summary of what lead to this problem of mine in case it helps)