Hey Lambchops -
So we are still testing some things but I wanted to let you know of a fix we found earlier in the testing process so at least you can get back up and working. Create a new Blank Project with No Starter Content, let the engine open it and then immediately close. Copy all contents from the Original Project’s Content folder (Content folder only not the uproject file or the saved or intermediate folders) and place it into the new project’s content folder. Open the new project again and from the content browser open your main map. Re-enable the Distance Field Ray Trace and restart the editor and you main map.
You should be back up and running again. We will continue to diagnosis the visual banding and let you know if we find a more directed solution.
Thank You
Eric Ketchum