If you try a url, such as /foo it results in a lengthy log:

2019-04-30 15:20:14.247 ERROR 14280 — [nio-8080-exec-2] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]

javax.servlet.ServletException: Circular view path [error]: would dispatch back to the current handler URL [/error] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.)
at org.springframework.web.servlet.view.InternalResourceView.prepareForRendering(InternalResourceView.java:209) ~[spring-webmvc-5.1.4.RELEASE.jar!/:5.1.4.RELEASE]
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:147) ~[spring-webmvc-5.1.4.RELEASE.jar!/:5.1.4.RELEASE]
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:316) ~[spring-webmvc-5.1.4.RELEASE.jar!/:5.1.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1370) ~[spring-webmvc-5.1.4.RELEASE.jar!/:5.1.4.RELE...