We are stuck to start the nifi service. We have restrted the cluster and started the service through nish.sh. The status is showing as running but URL is not coming. Further we checked the log and found the below exception into nifi-app.log. 2020-03-09 11:59:53,253 ERROR [main] org.apache.nifi.NiFi Failure to launch NiFi due to java.util.ServiceConfigurationError: org.apache.nifi.processor.Processor: Provider org.apache.nifi.processors.poi.ConvertExcelToCSVProcessor could not be instantiated     Nifi-app.log---------- 2020-03-05 18:15:19,666 ERROR [main] org.apache.nifi.NiFi Failure to launch NiFi due to java.util.ServiceConfigurationError: org.apache.nifi.processor.Processor: Provider org.apache.nifi.processors.poi.ConvertExcelToCSVProcessor could not be instantiated java.util.ServiceConfigurationError: org.apache.nifi.processor.Processor: Provider org.apache.nifi.processors.poi.ConvertExcelToCSVProcessor could not be instantiated at java.util.ServiceLoader.fail(ServiceLoader.java:232) at java.util.ServiceLoader.access$100(ServiceLoader.java:185) at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:384) at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404) at java.util.ServiceLoader$1.next(ServiceLoader.java:480) at org.apache.nifi.nar.StandardExtensionDiscoveringManager.loadExtensions(StandardExtensionDiscoveringManager.java:156) at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:131) at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:117) at org.apache.nifi.web.server.JettyServer.start(JettyServer.java:942) at org.apache.nifi.NiFi.<init>(NiFi.java:158) at org.apache.nifi.NiFi.<init>(NiFi.java:72) at org.apache.nifi.NiFi.main(NiFi.java:301) Caused by: java.lang.NoClassDefFoundError: org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler$SheetContentsHandler at java.lang.Class.getDeclaredConstructors0(Native Method) at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) at java.lang.Class.getConstructor0(Class.java:3075) at java.lang.Class.newInstance(Class.java:412) at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380) ... 9 common frames omitted Caused by: java.lang.ClassNotFoundException: org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler$SheetContentsHandler at java.net.URLClassLoader.findClass(URLClassLoader.java:382) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357)   ... View more

Nifi was working fine and we have rebooted the server. After that Nifi is not starting at all. Nifi status is show as running but UI is not coming at all. Please find below The same server is having cloudera 6.3 server as well. The nifi-app.log is showoing below mentioned exception. Can anyone help on this regards? ---- XXXXXXX# ./nifi.sh status nifi.sh: JAVA_HOME not set; results may vary   Java home: NiFi home: /home/nifi/install/nifi-1.11.0   Bootstrap Config File: /home/nifi/install/nifi-1.11.0/conf/bootstrap.conf   2020-03-10 13:00:24,014 INFO [main] org.apache.nifi.bootstrap.Command Apache NiFi is currently running, listening to Bootstrap on port 39661, PID=3886   --   2020-03-09 11:59:48,526 INFO [main] org.apache.nifi.web.server.JettyServer Loading WAR: /home/nifi/install/nifi-1.11.0/./work/nar/framework/nifi-framework-nar-1.11.0.nar-unpacked/NAR-INF/bundled-dependencies/nifi-web-error-1.11.0.war with context path set to / 2020-03-09 11:59:48,558 INFO [main] org.apache.nifi.web.server.JettyServer Running in HTTP mode; host headers not restricted 2020-03-09 11:59:53,253 ERROR [main] org.apache.nifi.NiFi Failure to launch NiFi due to java.util.ServiceConfigurationError: org.apache.nifi.processor.Processor: Provider org.apache.nifi.processors.poi.ConvertExcelToCSVProcessor could not be instantiated java.util.ServiceConfigurationError: org.apache.nifi.processor.Processor: Provider org.apache.nifi.processors.poi.ConvertExcelToCSVProcessor could not be instantiated                 at java.util.ServiceLoader.fail(ServiceLoader.java:232)                 at java.util.ServiceLoader.access$100(ServiceLoader.java:185)                 at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:384)                 at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)                 at java.util.ServiceLoader$1.next(ServiceLoader.java:480)                 at org.apache.nifi.nar.StandardExtensionDiscoveringManager.loadExtensions(StandardExtensionDiscoveringManager.java:156)                 at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:131)                 at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:117)                 at org.apache.nifi.web.server.JettyServer.start(JettyServer.java:942)                 at org.apache.nifi.NiFi.<init>(NiFi.java:158)                 at org.apache.nifi.NiFi.<init>(NiFi.java:72)                 at org.apache.nifi.NiFi.main(NiFi.java:301) Caused by: java.lang.NoClassDefFoundError: org/apache/poi/xssf/eventusermodel/XSSFSheetXMLHandler$SheetContentsHandler                 at java.lang.Class.getDeclaredConstructors0(Native Method)                 at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)                 at java.lang.Class.getConstructor0(Class.java:3075)                 at java.lang.Class.newInstance(Class.java:412)                 at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380)                 ... 9 common frames omitted Caused by: java.lang.ClassNotFoundException: org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler$SheetContentsHandler                 at java.net.URLClassLoader.findClass(URLClassLoader.java:382)                 at java.lang.ClassLoader.loadClass(ClassLoader.java:424)                 at java.lang.ClassLoader.loadClass(ClassLoader.java:357)                 ... 14 common frames omitted ... View more