Have you run a map check for “ThirdPersonExampleMap2?” (You have to run a map check for each map/level individually)
Are you not able to find the blueprint that includes: "event node K2Node_ActorBoundEvent_0? -Have you checked the level blueprint for “ThirdPersonExampleMap2?”
Have you disabled any Plugins that may have been referencing this node? Are there any plugins currently enabled? If so try disabling them.
Finally, right-click the Contents folder in the Content Browser and choose “Fix up redirectors in Folder.” Save all.
In addition to the Intermediate and Saved folders, try deleting the Config folder from the Project folder (after making a backup to restore your Project and Editor Settings in the event this step does not help).
You can also try deleting the DerivedDataCache folder from the Engine installation folder.
Try these steps and if they do not work, respond with the requested information above.