William Lane Craig denies the number zero.

[Edwardo Piet]

The number zero obviously exists.

Aren't you the guy who said that existence isn't a property?

It isn't.

Now you're telling me that something with no properties exists? C'mon.

No I'm not. Who says the number zero has no property? The number zero is a concept and concepts exist in the brain.

The way I see it is asking "does the number zero exist?" equates to asking "is the number zero anything at all?" or in other words "is the number zero a thing at all?" since the answer is "yes" it's a thing and therefore existent.