The styling is inline. It is not coming from my css or javascript. I’ve tried using the regions’ css over-rides, but they have no effect. Here is a screenshot of the page when in layout mode.
You can imagine how difficult is to work on a layout that is 30430px wide. I should also note that the issue goes away when I switch to content view and does not affect how the page looks in preview.
It looks like it’s either from template level or page level where you added div region. It does give strange fixed width and height. Very annoying.
I’m not sure I am following your comment. The #page region, is the first region on the page. If you were to make a new plain template, the region would be called perc-container. This is not a region I added; I just changed the name.
I understand what you mean. If you go to Layout tab, double click that region and it should bring up the dialog window, go and find that showed width and height in CSS override - remove the #s. See attached:
I did try that. I mentioned it in the original post. Those overrides are empty. Before posting, I also tried entering reasonable pixel widths in those fields and and I tried checking the ‘Do not use CSS overrides’. Thank you for your suggestion.
That’s odd. Yeah, probably a good idea for Tech Support to look at it 
For future visitors, I was able to narrow down the css in my code that causes the issue. I would like to point out that it is NOT the error, but seems to cause the percussion layout view renderer to go haywire. The offending css has width:100% and is responsible for a couple of background images in the masthead. When I remove the 100%, the layout view renders fine, but this, of course, wrecks my masthead. I have no solution for this currently, but I’m hoping someone who understands how the layout view works behind the scenes will have some ideas.
We were able to resolve this issue by placing max-width:100% on the container that the width:100% are inside of. Thank you again, Chris and Casey.
This is what I needed. Thank you.