Board Thread:Support Requests - Designing Your Wiki/@comment-1994841-20181001150535/@comment-1038387-20181001160018

None that I'm aware of, but I'm not that code savvy. It could be it's broken by a sitewide update that makes it clash with other code. You could check Technical Updates for something relevant, though they don't list all changes on there.

You've not mentioned what you want for a background, but all I'm seeing is white with a light blue translucent band down the center. If that's what you added, it's probably related to your personal js or css.