I just encountered this error and the cause was that I had 2 firebase tools installed. One was through homebrew and the other was local. You can see if this is the case for you by running these command in terminals:

which firebase

npm list -g firebase-tools

If the output of those commands is different, you have the same problem I did.
In my case, removing the local library solved the issue:

rm /Users/mycomputer/.local/bin/firebase

You should also make sure you are on the latest version. Compare the output from this command:

firebase-tools -v

with the github latest version: https://github.com/firebase/firebase-tools