My Publish Online feature keeps failing (InDesign)

This is the error message I keep getting when trying to publish my document online. I have posted online many times and usually get this message a few times, but through persistent attempts, I finally get the link to post. However, I have tried multiple times with different file sizes (dividing the document into two parts), and I continue to get this error message. I have been back and forth with our IT department in previous attempts when this happens and we haven't found a solution.