Freeze when clicking in the binder

When I click on a chapter that’s on the left sidebar having an icon that is Yellow, I get the MAC spinning wheel until I force quit the software. Not sure how, or why the chapter icon is yellow. I did nothing to initiate that change. I have two chapters that freeze the SW when accessed-both have the yellow color on the icon. Using Mac 10.15.5 Catalina.

I can’t work on my manuscript until I fix the freezes. I’m trying to send my book to a publisher!!!