Why is codex suddenly giving me this error?

Was working fine then all of a sudden every prompt returns:

{ "success": false, "error": { "name": "ZodError", "message": [ { "code": "invalid_union", "errors": [], "note": "No matching discriminator", "discriminator": "type", "path": [ "tools", 5, "type" ], "message": "Invalid input" } ] } }