Having a mob spawn falling meteors from the Nyx mod routinely results in a crash. This worked fine at one point before - I think the difference may be in the two similar spawn methods (same master-summon identity, plus the identifier) The unique identifier (1 and 2) might be checking for something that does not exist in non-living entities, which is why this crashed where before a single line worked normally.

https://paste.ubuntu.com/p/QYG9qZG3YV/

The lines in question:

        null:king_slime;nyx:falling_meteor;70;1-1;60-80;false;false;0;false;false;false;{size:2,homing:1b,spawnNoBlock:1b,disableMessage:1b,speed:0.35};1

        null:king_slime;nyx:falling_meteor;50;3-3;20-30;false;false;0;false;false;false;{size:1,homing:1b,spawnNoBlock:1b,disableMessage:1b,speed:0.45};2