This is Firefox uniform3fv issue test example.Please open console (F12) to see test result.

		Normally you should see this:

		Vertex log:
		Fragment log:
		Link log: 
		v3Loc: [object WebGLUniformLocation]
		Setting v3 uniform...
		optimizedOutLoc: null 
		Setting optimizedOut uniform...

		In Firefox 75 and 76 the following message also appears:
		WebGL warning: uniform setter: `values` length (4) must be a positive integer multiple of size of .
		and WebGL error state is set to GL_INVALID_VALUE