All the lines of my drawing disapeared

I have been working in a file for several days, and today I opened to add a new layer.

Everything was working fine, but suddenly all my lines disapeared.

Originally, I tough it was a zoom problem, I tried auto zoom without success.

I closed and opened the file and the it keeps the same.

It is weird because all the layers are there but I can not view anything either add new lines. It only shows the extreme points as dots.

If I open a new file everything works as intended.

I don't know what to do and I don't want to start all over again.

Thanks for your help
 
I attach the file for reference.

Casa.dxf

-Some layers had the lock activated
-Some layers were hidden
-If you press Ctrl+A you select all the elements of the drawing and it will show you where the objects are. They were simply zoomed in too far. Zoom in on the objects and they will appear.

Casa.dxf