If you were trying to upload a 2.3MB zip file to our server as a post attachment, it would fail as the filesize limit is 500KB. Based on your wording though, you were trying to transfer it using our Upload service -- is that correct?
If so, try uploading the file again... or otherwise try again using said service. If the problem persists, follow-up here with as detailed a report on e.g. what error message(s) you received including screenshot(s).