THREE.WebGLRenderer: Error creating WebGL context.

[pengMaster]

THREE.WebGLRenderer: Error creating WebGL context.
console.error @ VM111:1
WebGLRenderer @ three.js:21448
restart @ main.js? [sm]:34
Main @ main.js? [sm]:29
(anonymous) @ game.js? [sm]:6
require @ WAGame.js:3
(anonymous) @ gamePage.html:124
VM111:1 gameThirdScriptError
Cannot read property 'getExtension' of null
TypeError: Cannot read property 'getExtension' of null
at Object.get (http://127.0.0.1:34644/game/js/libs/three.js:20889:21)
at initGLContext (http://127.0.0.1:34644/game/js/libs/three.js:21464:15)
at new WebGLRenderer (http://127.0.0.1:34644/game/js/libs/three.js:21510:3)
at Main.restart (http://127.0.0.1:34644/game/js/main.js:55:18)
at new Main (http://127.0.0.1:34644/game/js/main.js:48:10)
at http://127.0.0.1:34644/game/game.js:13:1
at require (http://127.0.0.1:34644/game/__dev__/WAGame.js:3:14317)
at http://127.0.0.1:34644/game/gamePage.html:124:5