Failed to start service due to '(HTTP code 500) server error - invalid character 'c' looking for beginning of value '

Not really sure what to do, each release I’ve updated has been successfully created with no errors.

I’ve reverted back to previous builds that work but keep getting this error no matter what.

It looks like I am getting a npm ERR! cb() never called! error in my build but I’ve reverted back to a previous build that has worked in the past which makes me think it’s a caching error.