what is this
How to troubleshoot
How to solve the problem
Is there no answer?
I have not seen that in some time but if memory serves that usually happens from an assembly exploded view and broken views like you have shown. The only way I had fixed it in the past was with doing a "Crop View" of the offending view to get the sheet to show correctly on screen. Otherwise as I'm sure you're seeing, the page will never seem to properly zoom when you try to zoom to fit.
Check out the "Crop View" here ...
SW Help page ...
That is a View boundary in your drawing. If you grab its edge you can drag it. Also by selecting it you should see in your FeatureManager tree which view it is. There could be some/all items in that view that are hidden, or it could be part of one of your intended views that has a part way out in space. The view boundary will be an envelope to encompass all things that are viewable.
I agree with Dennis. Something is floating out there.
Solidworks 2015 introduced a new "zoom to sheet" command. If you use that, those views whose borders extend beyond the sheet aren't as annoying.
In addition to the standard keyboard shortcut F for zoom to fit, I mapped Alt-F for zoom to sheet. Comes in very handy.
Have you inserted a selected body view which is at different orientation in the model
Retrieving data ...