Blue mist covering my plan

[Keith_K]

If the whole thing still highlights, you haven't found the bad connection yet, so keep going around the building until you do.

And that, Kat, is the sort of advice that people like me look for when coming here. I zoomed in as far as practicable and, jerk by jerk, started going around the walls and then I found it, managed to fix it and the blue mist has now evaporated. Thank you.