For client side applications, the workaround is to get the rendering process out of the background thread. But for windows services that doesn't work, because there is no UI thread.System.InvalidOperationException: The calling thread must be STA, because many UI components require this.
Why does RenderWithWPF needs access to the UI thread, unlike the Render method?
How can RenderWithWPF() work in a background thread?
Note: I already set the "DisplayProgress" to false.