Upgrading from 4.7.25 to 5.6.0 breaks CiviCRM
Jack,

There seems to be problem with the extensions you have installed. Try upgrading CiviCRM after disabling all the extensions. Some extension might not be compatible with latest version of CiviCRM. As a best practice we disable all the extension or plugin of CiviCRM and then perform CiviCRM upgrade. Once finished with upgrade we turn on extension or plugin one by one.

HTH

Pradeep