message: Fix for 'attributes is null' exception on mobile
diff: @@ -280,7 +280,7 @@ export class ContextSystem implements ISystem
  }
  // this is going to be fairly simple for now.. but at least we have room to grow!
  - if (!attributes.stencil)
  + if (attributes && !attributes.stencil)
  {
  /* eslint-disable max-len, no-console */
  console.warn('Provided WebGL context does not have a stencil buffer, masks may not render correctly');
  