Update TESTCASES.md

TESTCASES.md

@@ -308,7 +308,7 @@ The tileset renders and loads correctly.
 
 #### steps
 
-1. Open the kitchen sink example with the no root content tileset by navigating [here](https://nasa-ammos.github.io/3DTilesRendererJS/example/bundle/#../data/tileset-add.json).
+1. Open the kitchen sink example with the no root content tileset by navigating [here](https://nasa-ammos.github.io/3DTilesRendererJS/example/bundle/#../data/tileset-broken-root-content.json).
 1. Set `colorMode` to `RANDOM_COLOR`.
 
 #### expected