missing objects in model space autocadd 2014

[Anonymous]

yesterday we experienced a problem.  we have a drawing file, is about 1.6meg not big. while working in model space doing some 3D work, all of a sudden all the objects dissapear except for some text.  all layers are on and thawed. we regen all, zoom all. weird thing is when we go into the paper space tabs everything shows up. so all the data is there some place but cant find it in model space.  any ideas on where to start.  hope some one hear is able to help.

there are no xrefs in the drawings and i had cleaned all the multiple copies out before to keep the file size down and more workable.  this is happening on two machines. other drawings are fine.

[Anonymous]

other odd thing is if i change view to anything except the top view i can see everything. so it is only occuring in the top view.

[Anonymous]

ok so this morning after flipping around in the tabs and seeing everything there i went back to model space still nothing there in top 2d wireframe. i switch to a isometric then to a camera i had set up, which changes everything to 3d wireframe, went back to top view and switched to 2d wireframe and everything was back.  this is so annoying having it just fix itself. i was so fustrated yesterday i left a hour early because i could not do anything.  guess until it happens again i realy do not need any help.  thanks