FXAA Shader pass is black

[avaer]

The THREE.js FXAA example renders an error and blackness:

https://threejs.org/examples/webgl_postprocessing_fxaa.html

[avaer]

Error stack:

(node:15712) ExperimentalWarning: vm.SourceTextModule is an experimental feature. This feature could change at any time
THREE.WebGLRenderer 106
THREE.WebGLProgram: shader error:  1286 35715 false gl.getProgramInfoLog Fragment info
-------------
0(804) : error C1503: undefined variable "FxaaTexGreen4"
0(805) : error C1503: undefined variable "FxaaTexOffGreen4"
(0) : error C2003: incompatible options for link  THREE.WebGLShader: gl.getShaderInfoLog() fragment
0(804) : error C1503: undefined variable "FxaaTexGreen4"
0(805) : error C1503: undefined variable "FxaaTexOffGreen4"1: #version 330
2: #extension GL_ARB_separate_shader_objects : enable
3: 

[avaer]

Partial fix: avaer/webgl-to-opengl#6