Did I mention this is bizarre?
Okay, I have a couple of variant-themes. It would probably be easier to use one theme and but various backgrounds and other tweaks in dynamically, but 1. I don't know how to do it and 2. I think it will load faster if I hard-code.
So I've successfully copied a base theme several times and made numerous stylistic tweaks each time. Then I come to a particular domain where I am using a background image called bak-1.jpg. Usually I leave the code here the same and upload a new image, but sometimes I point to another image.
What I first thought that I determined through trial and error is that I get a bug when I use any name other than bak-1.jpg in my style sheet for the page background. The error is shows this at the top of the page:
God only knows how or why. I monkeyed with it for a long while and then just said, okay when then I don't have this problem on any of the other domains. I'll just make a new bak-1 and name it bak-3 for those domains that use bak-1 and then I'll overwrite bak-1 with the look I want.
But here's where it takes a turn for the truly bizarre. If I leave the file name the same but change the image to another look---I get the error. In other words, something as simple as a color change in the image makes the page break. I'm at a loss as I can't even imagine how or why this is the case.