MS Project Import - Task dependencies, milestones and WBS not imported

MS Project Import - Task dependencies, milestones and WBS not imported

New to Zoho.  I've uploaded an MS Project from project 2013 and the dependencies & successors in project (Predecessors and Successors in Zoho) weren't populated, milestones weren't uploaded, and the work break down structure was lost.

Did I do something wrong in the upload?