saveInBackground method causes error: The data couldn’t be read because it isn’t in the correct format.

[agordeev]

Issue Description

I have a class called Image, which has image property of PFFile type. When I'm trying to create a new object by calling saveInBackground method, the server returns this error:

Error Domain=NSCocoaErrorDomain Code=3840 
"JSON text did not start with array or object and option to allow fragments not set." 
UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}

error.localizedDescription:

The data couldn’t be read because it isn’t in the correct format.

Save operations on other classes work fine. The server log doesn't even show that there is POST request to Image class.

Any ideas what's wrong?

Environment Setup

• Server
  • parse-server version: 2.2.14.
  • parse-dashboard version: 1.0.14
  • Operating System: Ubuntu 10.14
  • Localhost or remote server? (AWS, Heroku, Azure, Digital Ocean, etc): DigitalOcean

[agordeev]

It's better realted to Parse iOS SDK, so I reposted the issue there: parse-community/Parse-SDK-iOS-OSX#952