1. Have you tried Track spline mode? Sometimes I've seen scenery splines glitch and show up in the Tracks tab.
2. Do you know the kuid number? If so, and the asset isn't used anywhere else in your layout, you could delete it from CM, do a DB rebuild to make sure it's gone from the database. This should now make it a "missing dependency" in your layout. Open the layout again and use "Delete Missing Assets" to clear the missing dependencies error.
3. Hire Conchita to scrub that green mess off with Lemon Pledge.
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