Why does a viewport show the wrong part of my drawing?

[indiancad]

I recently ran into a layout where the viewport was showing the wrong area of the model, even though the model itself was correct.

 

At first I thought the viewport had been moved or resized.

 

The simple fix was to activate the viewport and use ZOOM > Object or PAN to position the view correctly.

 

One thing I also check now is whether the viewport is locked, because a locked viewport can make it confusing when trying to adjust the view.

 

It reminded me that sometimes the drawing is fine and the problem is only with the viewport settings.

 

How do you normally troubleshoot a viewport that suddenly shows the wrong area?

[CyberAngel]

What often happens to me is that I unlock the viewport to move something, and then I forget to lock it again when I'm done. Later I use the viewport but forget it's unlocked. I zoom in and out to focus on something but affect the model view instead of the viewport.

 

Wherever possible, I use a border in model space (on a nonplot layer of course) to show the edges of the viewport. Then, if something changes the view, it's easy to get it back to the proper scale/location.

 

It would be nice if AutoCAD had a way to save views for you. Revit has that feature, but for some reason AutoCAD doesn't.