When I opened my inkscape file today, all layers are there but the objects and paths are not visible, below each layer there is a layer 1 coming  and that is also blank. Please help as I had designed a 100 pg book and all is gone. Thank you. 

Nothing is gone; all is set to "invisible". Select all and click the "Eye-icon".

I did that, made all layers visible still no data. Thank you

Can you go here please Layers and Objects->Cog wheel icon and uncheck "Only show layers"?

It was already unchecked. thank you

Not sure how you went there, but it seems empty indeed. Check under Preferences->System->Temporary files: the location where these are stored if there´s anything left.

The file size could be an indicator or dragging it into a browser window or checking View->Display mode=normal.

I was able to recover the file from the temporary files. Thank you so much. Truly appreciate your help. 

Glad you found what you need. 😉

@Polygon : on last screenshot the small "screen" icon in top right corner indicates display mode is set to normal.

@Madhumira : on your last screenshot, status bar, bottom right, displays informations indicating that the selected Sub-Layer 1 does not contain any object.

@David248 no clue which icon you´re talking about as I have a totally different Inkscape layout and no View mode icon is present here. And just the whale layer resp. its Layer 1 is selected in screenshot and though the Status Bar is just referring to this specific layer.

@Polygon

1. Of course, status bar only refers to the selected object, ie the highlighted object in object and layers panel. TBO, I don't understand the structure displayed by object's panel in this screenshot. Status Bar refers to a group hosting this Layer 1, if I don't misunderstand. I was just pointing out, that, to me, Layer 1 is empty.
2. Here are the icons I was refering to 😉. The second column of icons (with a grey dot, upper right of icon) correspond to the icons when color managed mode is on.