[Canvas] IllegalStateException when using PixelWriter.setColor

When writing more than one pixel to a canvas the error gets thrown when calling createSnapshot. But it works fine when only one pixel is written. The identical code works with JFX2 but not 8. (I'm using the current release of JFX8). This hapens in both Linux and Windows versions. And I'm doing the opps on the JXF thread called from on on action event.