Update logo image fails with Error 400

Step to reproduce:

• Browse to Configuration >> General
• Look & Feel Settings tab
• Insert a File (.png) on the Logo File and click save.
• Nothing happened (no feedback to the user)
• Checking the request.log shows error 400 on the post request of the with the following

  {
    "errors" : [ {
      "status" : 400,
      "message" : "{\"error\":\"no user logo found\"}"
    } ]
  }