Although reload failed, the game will also tell you "Disabled data pack [XXX]"

Although reload failed, the game will also tell you "Disable data pack [XXX]".

For example, when disabling the vanilla data pack, there will be two texts in chat: "Reload failed, keeping old data" and "Disabled data pack [vanilla]", and the data pack is still enabling.

The vanilla data pack can't be disabled is also a problem, you can see it here: MC-185302.