Missing Entity Strings

Here is The Problem.

I Noticed that My Version Has Missing Entity ID/Strings Like Fireball And Thrown_trident. They dont exist for Some odd reason. But not only That, my Friend and i Have the same Version(1.15.0.55). But those Missing Entity IDs that i Have been looking for is Availabble in Their Version. Thaf made me super Confused so i thoughg of this as A Bug.

I Bed you to Fux it please