Unexpected non-whitespace character after JSON at position 3 (line 1 column 4)

SyntaxError: Unexpected non-whitespace character after JSON at position 3 (line 1 column 4)
    at async Object.<anonymous> (functionsWorker-0.07735299484954283.js:3038:12)
    at async resourceFetcher (functionsWorker-0.07735299484954283.js:2346:22)