This is due to Realistic Ores relying a bit on the internal structure of this mod's files, which changed a bit with the redone graphics. I'd submit a PR but it looks like the version of Realistic Ores on github isn't quite up to date, so I settled for posting the one line fix in this thread that hopefully the author will see; you can unzip the mod and apply the fix to your local copy in the meantime.
The github repository is up to date. The master branch is for Factorio 0.16.x because this is still the official version on Steam (non experimental). You can checkout branch x.17.x of my repo to see the latest changes.
