This topic describes the types of error messages returned with HTTP status code 411, and the common causes and solutions to these errors.


  • Error message: You must provide the Content-Length HTTP header.
  • Cause: The request does not use chunked encoding or does not contain the Content-Length header.
  • Solution: Use chunked encoding to encode request headers or include the Content-Length header in the request.


  • Error message: The object is not appendable.
  • Cause: You have performed the AppendObject operation on an object that is not uploaded by using append upload.
  • Solution: Check the type of the object on which you want to perform the AppendObject operation. OSS objects can be categorized into three types based on the upload method: normal objects, append objects, and multipart objects. The AppendObject operation can be performed only on append objects. You can call the GetBucket (ListObjects) operation to obtain the type of an object.