File suddenly become blank & entire model disappear

This is a guess as to what happened and how you may be able to avoid it in the future.

There has been a history of this kind of experience with systems having an Intel graphics adapter (card) . The only workaround that I am aware of is to remove your 64-bit version of SketchUp and replace it with the 32-bit version. For some unknown reason, the 32-bit version works acceptably with the Intel graphics card and SU 2016.

After you uninstall the 64-bit version, you can download the 32-bit version of the same release by clicking the following url link: http://www.sketchup.com/download/all

Hopefully this works for you. Typically the file should still remain on your system, but you may need to perform a search using the date and/or filename or other criteria to locate it now.