1. A concise explanation of the problem you're experiencing.
A site I play on www.geo-fs.com usually runs perfectly. Today, I launched Firefox Developer Version 57b12, and everything runs fine, EXCEPT the aircraft rendering.
2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.
I have a screenshot of the error
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I want to make sure that this browser will work with this WebGL stuff
4. The Cesium version you're using, your operating system and browser.
Geo-FS uses Cesium 1.31