bug??

1. A concise explanation of the problem you're experiencing.
What is the cause of this problem?
Some computers do not have this problem, and some computers have this problem when Cesium is initialized.
RuntimeError: Program failed to link. Link log: C:\fakepath(134.9-30): error X3004: undeclared identifier 'AtmoshpereColor'

Warning:D3D shader compilation failed with default flags. (vs_3_0)
Retrying with avoid flow control
C:\fakepath(134.9-30): error X3004: undeclared identifier 'webgl_cd16f13802bc8948'

Warning:D3D shader compilation failed with avoid flow control flags. (vs_3_0)
Retrying with prefer flow control
C:\fakepath(134.9-30): error X3004: undeclared identifier 'webgl_cd16f13802bc8948'

Warning:D3D shader compilation failed with prefer flow control flags. (vs_3_0)
Failed to create D3D shaders.

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

4. The Cesium version you're using, your operating system and browser.
  version 1.51. window64. Google Chrome

Do you know which computers are having this issue and which are not?

This is the closest bug report I’ve found to this:

https://github.com/AnalyticalGraphicsInc/cesium/issues/2197

Make sure to update the browser and any graphics drivers. And if you can provide some more info on what browser version and OS is on the failing computers that would help.