Problem deleting surfaces - the whole model gone

Hello people.

i’m using SketchUp Make 2015 (currently Pro for a month) in order to analyse my model with desighPH plugin. Initial model is created in Archicad, therefore there are way to many surfaces for my purpouse. As i start deleting what i don’t need at some point the whole model is not visible anymore. Nothing is hidden, all the Layers on… i wonder if i’ve managed to delete the whole thing but my groups are there (if it is of relevance). Anyway Undo does not help. Please tell me what i\m doing wrong and how cani get my model back.

Best regards,
Anastasia Ducke

If you have not closed your model yet, save a copy(File/Save a copy as) of your model then try the Revert function(File/Revert) and see what happens.
Try Zoom extents (Shift+Z) or your custom shortcut.
Check the hidden geometry(View/Hidden geometry).
If the geometry was grouped as components and you delete it you can bring them back from the Components browser(in model).

Thank you, @ely862me

i have closed the file already, but i’d know what to do when it happends again (was several times already).

If you used components, they may still be in the component window. Or if there is an older file with a skb file extension besides your model file, it’s a backup from before the change eventually.