Openfire 4.6.0 Monitoring Service plugin not working

Hello. Now I have Openfire 4.6.0 with Monitoring Service 2.2.1, but before that there was a previous version of the plugin. The error lies in the fact that the plugin is not in the web panel. And this problem has been around for a long time.
This problem occurred after one of the Openfire updates. It happened on this line - I don’t remember.
Logs:

2021.03.04 16:15:25 ERROR [pool-33-thread-1]: org.jivesoftware.util.XMLProperties - Error reading XML properties
org.dom4j.DocumentException: Error on line 1 of document  : Premature end of file.
        at org.dom4j.io.SAXReader.read(SAXReader.java:511) ~[dom4j-2.1.3.jar:?]
        at org.dom4j.io.SAXReader.read(SAXReader.java:408) ~[dom4j-2.1.3.jar:?]
        at org.jivesoftware.util.XMLProperties.buildDoc(XMLProperties.java:740) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.util.XMLProperties.<init>(XMLProperties.java:163) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.util.XMLProperties.<init>(XMLProperties.java:123) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.index.LuceneIndexer.loadPropertiesFile(LuceneIndexer.java:413) [monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.index.LuceneIndexer.start(LuceneIndexer.java:68) [monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.plugin.MonitoringPlugin.initializePlugin(MonitoringPlugin.java:201) [monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.container.PluginManager.loadPlugin(PluginManager.java:683) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:375) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:363) [xmppserver-4.6.0.jar:4.6.0]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_275]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_275]
Caused by: org.xml.sax.SAXParseException: Premature end of file.
        at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1473) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1014) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213) ~[?:1.8.0_275]
        at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643) ~[?:1.8.0_275]
        at org.dom4j.io.SAXReader.read(SAXReader.java:494) ~[dom4j-2.1.3.jar:?]
        ... 14 more
2021.03.04 16:15:25 ERROR [pool-33-thread-1]: org.jivesoftware.openfire.archive.ArchiveIndexer[CONVERSATION] - An exception occurred while initializing the Lucene index t$
java.io.IOException: Error on line 1 of document  : Premature end of file.
        at org.jivesoftware.util.XMLProperties.buildDoc(XMLProperties.java:744) ~[xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.util.XMLProperties.<init>(XMLProperties.java:163) ~[xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.util.XMLProperties.<init>(XMLProperties.java:123) ~[xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.index.LuceneIndexer.loadPropertiesFile(LuceneIndexer.java:413) ~[monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.index.LuceneIndexer.start(LuceneIndexer.java:68) [monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.plugin.MonitoringPlugin.initializePlugin(MonitoringPlugin.java:201) [monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.container.PluginManager.loadPlugin(PluginManager.java:683) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:375) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:363) [xmppserver-4.6.0.jar:4.6.0]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_275]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_275]
2021.03.04 16:15:25 ERROR [pool-33-thread-1]: org.jivesoftware.openfire.container.PluginManager - An exception occurred while loading plugin 'monitoring':
java.lang.NullPointerException: null
        at org.jivesoftware.openfire.index.LuceneIndexer.getLastModified(LuceneIndexer.java:143) ~[monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.index.LuceneIndexer.start(LuceneIndexer.java:124) ~[monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.plugin.MonitoringPlugin.initializePlugin(MonitoringPlugin.java:201) ~[monitoring-2.2.1.jar!/:?]
        at org.jivesoftware.openfire.container.PluginManager.loadPlugin(PluginManager.java:683) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:375) [xmppserver-4.6.0.jar:4.6.0]
        at org.jivesoftware.openfire.container.PluginMonitor$MonitorTask$4.call(PluginMonitor.java:363) [xmppserver-4.6.0.jar:4.6.0]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_275]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_275]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_275]

Restarting the server or Openfire didn’t help. And reinstalling the plugin didn’t help.

Description: Debian GNU/Linux 9.12 (stretch)
Release: 9.12

java -version
openjdk version “1.8.0_275”
OpenJDK Runtime Environment (build 1.8.0_275-8u275-b01-1~deb9u1-b01)
OpenJDK Server VM (build 25.275-b01, mixed mode)

Please tell me.