When a crate that a player activated locked hackable crate hits 0, it doesnt allow them to loot the crate. It says 'You can not use this entity because it is not yours!'

I added "hackablelockedcrate" to "ExcludeEntities" and set "UseExcludedEntities" to true, which fixed it temporarily but popped right back up, even after a plugin reload.

I checked it out for you. I have no problem with this crate.
And the crate is not called that:

codelockedhackablecrate
codelockedhackablecrate_oilrig​