In my case it was a blocked impeller, which had not been cleaned for 10 years we have had the dishwasher. To get to the impeller, remove the (usually silver) mesh as you do when you clean the filter. There is a plastic pipe, hump arrangement held in place by a wire clamp. Flip clamp off - toward the filter side (use screwdriver if fingers not enough). Pull out plastic pipe. underneath is the impeller and you can see if there is gunk there. If so, remove using fingers, screwdriver, anything that will get it out. Spin impeller to make sure all gunk is out, also to see if it is able to spin freely. You can also clean the pipe, black rubber stopper and steel ball inside th epipe. Just make sure you have a good look how it is asssembled. replace all parts to the way it was. Run a cycle and see if
lights still flash. If so, problem is elsewhere, but at least you know that this is not the problem. calling out a Miele technicin to clean your impeller would be rather uneconomic.