Please see the attached sample project, which demonstrates the crash. I have only tested this in 4.17, not 4.18 yet.
Open the sample project and open the UMG widget blueprint. Go to the graph and make sure a breakpoint is set on the Tick event node. Run the sample and you will hit the breakpoint. Now click on the Resume button (you might need to Alt+Tab to get the mouse to it) and it should crash.