Runtime error: Unexpected token < in JSON at position 0
Hi, there! I'm having trouble integrating the apollo-upload-client into my app. I keep getting the error in the title above when uploading a file, so for good measure I've cloned this repo and just ran it (both the app and api). Same error as in my own app, the field 'operations' is present in the app from the repo and in my own.

Is this repo out of date? or am I doing wrong and how can I find out where the issue is?

Thank you in advance!