I might be a highlight for H&J or Keep violations (though in all the years I've worked with ID I've never seen such a violation). Check the prefs under Composition and see if those are checked on, and if so, try checking them off.
I didn't have either of them checked, and checking them didn't do any difference.
(also, preflight shows 'no errors', if that helps any..)
We'll have to wait, I guess, for someone from the pre-release group who has seen this to tell us what it means.
It seems like new paragraph shading feature in InDesign CC 2015.
Go to Type > Document Footnote options... and check the paragraph style applied. Check that paragraph style setting to validate if paragraph shading is active for it or not, if yes then disable it.
It doesn't seem to be a paragraph shading. The above picture shows how the paragraph looks like without shading, and below is a picture with the shading on.
Without paragraph shading:
With paragraph shading on:
I think you can see the difference, the shading goes all the way to both margins, and in the above situation the line is specifically over the text only.
We're aware of some issues with greeking of text in ID CC 2015. We're working on a fix.
Meanwhile, you can use the following workaround : open Preferences > Display Performance and set the 'Greek Type Below' to 0 pt.
that "fixed" it, but I still don't quite understand why..
The developers are currently overhauling the screen drawing engine of InDesign making it faster.
Some bugs sneeked in. This is one of them, I guess.
Or: Why is this fixing it?
No greeked text, no bugs with greeking text.
THANK YOU! Unchecking the H&J and Keep Violations worked!