If Cakewalk SoundCloud is closed, by clicking on the “X” in the upper right hand corner or the window, prior to uploading a file, you may see an error message stating:
 

“Warning: The External Encoder returned an error code. The File may not have encoded properly.”

This is because the External Encoder did not complete the process of creating and uploading the file to SoundCloud. If you closed Cakewalk SoundCloud and want to upload the file, you must re-export the file from Music Creator.