Unexpected token 'e', "error code: 1016" is not valid JSON

SyntaxError: Unexpected token 'e', "error code: 1016" is not valid JSON
    at async fetcher (functionsWorker-0.1934667529547689.js:3649:18)
    at async createRouteData.key (functionsWorker-0.1934667529547689.js:3796:22)
    at async resourceFetcher (functionsWorker-0.1934667529547689.js:2817:22)