It may happen that when clicking on "Orders" or "Plans" tab, its content do not get displayed, see for instance attached OMSUI.png. Also, below error is logged in omsui-local.log file:
===
2 Apr 2020 15:22:23,104 ERROR [] [] [] [org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/]] [] - Exception while dispatching incoming RPC call
java.lang.RuntimeException: java.lang.NullPointerException
        at org.gwtwidgets.server.spring.GWTRPCServiceExporter.handleExporterProcessingException(GWTRPCServiceExporter.java:344) ~[gwt-sl-0.1.5.jar:?]
        at org.gwtwidgets.server.spring.GWTRPCServiceExporter.processCall(GWTRPCServiceExporter.java:313) ~[gwt-sl-0.1.5.jar:?]
....
....
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51]
Caused by: java.lang.NullPointerException
        at javax.servlet.GenericServlet.getServletName(GenericServlet.java:236) ~[tomcat-embed-core-8.5.51.jar:8.5.51]
        at javax.servlet.GenericServlet.log(GenericServlet.java:188) ~[tomcat-embed-core-8.5.51.jar:8.5.51]
.....
===

Please refer to attached  omsui-local.log for full trace.