WebGL error when using DisplayPassPostProcess

Every time i use the DisplayPassPostProcess i get errors in the console (tested with Edge, IE, Chrome and Firefox on two machines ). The post processing is working as expected but maybe there are some other side effects because of that error.
Chrome error: WebGL: INVALID_ENUM: activeTexture: texture unit out of range
Firefox error: Error: WebGL: ActiveTexture: texture unit 0 out of range. Accepted values range from TEXTURE0 to TEXTURE0 + 32. Notice that TEXTURE0 != 0.

here a playground: http://www.babylonjs-playground.com/#3JGHY