API returns 500 errors for things that should be 404s, 403s, etc.

Reproductions:

Using the Retrieve License API with an ID that does not exist returns a 500 with "Resource not found." in the response body JSON.

Using the Retrieve License API with an ID on someone else's account returns a 500 with "You are not authorized." in the response body JSON.

Using the Delete License Activation API with an ID that has already been deleted returns a 500 with "Resource not found." in the response body JSON.