RoboHelp 2015 WebHelp output appends "_nc" to image
RH 2015, latest update
Windows 10
RoboHelp HTML, WebHelp output
We have a "NavigationPath" style in many topics to show users how they get to the user interface component, such as an Options pane, described in the topic. The style is bulleted, with the bullet being a "location pin" image named "navigation_2.png".

We have used this image for 2-3 years without any problem. Suddenly, over the last week, when we generate WebHelp output, RoboHelp renames the image, by adding "_nc" to the name: "navigation_2.png" becomes "navigation_2_nc.png". As a result, the output no longer shows the image. (I work around the problem by renaming the PNG without the "_nc", but would prefer to keep this from happening each time I generate the output.)
Has anyone experienced this bizarre issue?
Thanks.
Caro
