The given data was not valid JSON

I’m on p. 411 after the fix for remoteURL and the book says if I build and rum, I should now see photo parsing successfully. However, I get the following error:
Error fetching interesting photos: dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: “The given data was not valid JSON.”, underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 “Invalid value around character 0.” UserInfo={NSDebugDescription=Invalid value around character 0.})))

I have triple-checked that my code is the same as in the book/solutions. I can copy/paste if needed but I first figured I would ask if anyone has received this error and understands exactly what’s going on. I googled but it seems that if I have everything as it is in the book, it should work. Any thoughts?

Apparently, I needed to quadruple-check. I finally found the typo and it’s working now. “njsoncallback” will not work, only “nojsoncallback”.