CiviCRM upgrade from 4.2.7 to 4.7.13 fails to show any report
As I said to your previous post about the same topic here: What tables are used for civicrm reports?


  4.2->4.7 is a huge upgrade. Swathes of tables - including Activities and Settings - have changed. If you have any custom reports or
  extensions these definitely will need to be upgraded without a doubt.


As ErikH said:


  Assuming you are using customized reports and do not have a
  CiviCRM/PHP developer in your staff, you have to find a CiviCRM
  expert/developer to do this for you


Upgrading these reports will require a coder to change their code to point them to the new database tables used by CiviCRM. There's no workaround. Code for custom reports will need to be changed. Tell your next developer to use the CiviCRM API if possible!