Why did I enter the correct mobs ID,but it still told me unknown mobs?
Here is the my log:https://paste.ubuntu.com/p/k22qFgD6CW/
incontrol version:5.1.9
forger version:1.16.5-36.1.4

Are you sure those are the correct mob ids? How did you check that?
For example I see one error already: minecraft:sliverfish
That should be silverfish

minecraft:phatom is also wrong

mekanismaddition:baby_creeper is also wrong

rediscorverd:fish is probably wrong because I don't think the mod is called like that

What are you saying? I don't understand this:

But I've checked the wikis of these mods. These are the IDs of these mobs

Ah now I see. Anyway no. The ids are wrong. Check them again. There are several errors in them. i.e. see the errors that I gave you