java.lang.NullPointerException
	at java.base/java.util.Objects.requireNonNull(Objects.java:222)
	at net.sourceforge.plantuml.posimo.Path.<init>(Path.java:60)
	at net.sourceforge.plantuml.dot.CucaDiagramTxtMaker.<init>(CucaDiagramTxtMaker.java:118)
	at net.atmp.CucaDiagram.createFilesTxt(CucaDiagram.java:392)
	at net.atmp.CucaDiagram.exportDiagramInternal(CucaDiagram.java:416)
	at net.sourceforge.plantuml.classdiagram.ClassDiagram.exportDiagramInternal(ClassDiagram.java:83)
	at net.sourceforge.plantuml.UmlDiagram.exportDiagramNow(UmlDiagram.java:139)
	at net.sourceforge.plantuml.AbstractPSystem.exportDiagram(AbstractPSystem.java:207)
	at net.sourceforge.plantuml.servlet.DiagramResponse.sendDiagram(DiagramResponse.java:145)
	at net.sourceforge.plantuml.servlet.UmlDiagramService.doGet(UmlDiagramService.java:107)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:199)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:168)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	at org.apache.catalina.valves.StuckThreadDetectionValve.invoke(StuckThreadDetectionValve.java:185)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:383)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:937)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1791)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1190)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
	at java.base/java.lang.Thread.run(Thread.java:829)