The PCBReapir Tool will enable you to view your board view with .fz extension.
Click on CTRL+F11 to open from custom folder and CTRL+F10 to open from FAB folder.
Download boardviewer app for all board view extension, this boardviewer 2.1.0.8 version will allow you to view any board view files with the following extension (.BV .bvd .brd .f2b . asc .cad .gr .faz .tvw .cst .fz)