Extremely strange zooming and clipping plane issues

Hi there,

Out of no where I all of a sudden started experiencing terrible control over my zooming and navigation around the model. Even after zooming to a selected object when I zoom out I need to roll the wheel atleast 15 times to get the camera to even slightly step back. I did not group anything I did not manually change view settings nothing of that nature it just started happening. When I zoom back in slightly and take my hand off the mouse the model disappears. What is strange is this happened out of no where and a file with hundreds of hours of work into it seems to be helpless now due to this glitch it is almost impossible to work in. Please help.

Thank you!

(turn off all clipping planes until you solved the view-setting:
turn on all layers, _unhide all objects, _selClippingPlane and use property-window, clipping-plane page)

seams like you have some points / objects somewhere with really huge / endless dimensions.
try to manually set the camera-target to a well known point:
use this command / in the commandline to set the camera-Target
-_ViewportProperties _Target _Pause _Enter

you might also want to set the projection-mode to parallel:
-_ViewportProperties _Projection _Parallel _Enter

in one of the plan - view s (Top, Front, …) you can try to find endless data with select all / zoom selected

hope that helps, good luck, best Tom