I try to create system backup (xml), but get error: 

• There was a problem backing up data for the null plugin.

JIRA 7.2.6

Base: mysql

log:

2016-12-28 15:09:45,275 http-bio-443-exec-9 WARN m_titov 909x3059x1 1g1rufl 192.168.0.107 /secure/admin/XmlBackup.jspa [c.a.j.w.action.util.XmlBackup] The filename that will be used for exporting is: '/home/jira/atlassian/application-data/jira/export/backup.zip'
2016-12-28 15:09:48,844 http-bio-443-exec-9 INFO m_titov 909x3059x1 1g1rufl 192.168.0.107 /secure/admin/XmlBackup.jspa [c.a.j.bc.dataimport.DefaultExportService] Data export completed in 3567ms. Wrote 166538 entities to export in memory.
2016-12-28 15:09:48,848 http-bio-443-exec-9 INFO m_titov 909x3059x1 1g1rufl 192.168.0.107 /secure/admin/XmlBackup.jspa [c.a.j.bc.dataimport.DefaultExportService] Attempting to save the Active Objects Backup
2016-12-28 15:10:10,683 http-bio-443-exec-9 ERROR m_titov 909x3059x1 1g1rufl 192.168.0.107 /secure/admin/XmlBackup.jspa [c.a.j.bc.dataimport.DefaultExportService] Error during Active Objects Backup
com.atlassian.activeobjects.spi.ActiveObjectsImportExportException: There was an error during import/export with <unknown plugin>:
at com.atlassian.activeobjects.backup.ImportExportErrorServiceImpl.newImportExportSqlException(ImportExportErrorServiceImpl.java:26)
at com.atlassian.dbexporter.jdbc.JdbcUtils.withNoAutoCommit(JdbcUtils.java:57)
at com.atlassian.dbexporter.exporter.DataExporter$1.call(DataExporter.java:52)
at com.atlassian.dbexporter.exporter.DataExporter$1.call(DataExporter.java:49)
at com.atlassian.dbexporter.jdbc.JdbcUtils.withConnection(JdbcUtils.java:28)
at com.atlassian.dbexporter.exporter.DataExporter.export(DataExporter.java:49)
at com.atlassian.dbexporter.DbExporter.exportData(DbExporter.java:49)
at com.atlassian.activeobjects.backup.ActiveObjectsBackup.save(ActiveObjectsBackup.java:110)
at com.atlassian.jira.bc.dataimport.DefaultExportService.exportActiveObjects(DefaultExportService.java:184)
at com.atlassian.jira.bc.dataimport.DefaultExportService.export(DefaultExportService.java:86)
at com.atlassian.jira.bc.dataimport.DefaultExportService.export(DefaultExportService.java:67)
at com.atlassian.jira.web.action.util.XmlBackup.doExecute(XmlBackup.java:100)
... 1 filtered
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:63)
... 7 filtered
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
... 19 filtered
at com.softwareplant.ppm.structureint.jiraserver.event.PluginIssueLinkListener.doFilter(PluginIssueLinkListener.java:55)
... 37 filtered
at com.atlassian.servicedesk.internal.web.OperationalStatusAwareHttpFilter.doFilter(OperationalStatusAwareHttpFilter.java:31)
... 4 filtered
at com.atlassian.greenhopper.jira.filters.ClassicBoardRouter.doFilter(ClassicBoardRouter.java:62)
... 7 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 47 filtered
at com.xiplink.jira.git.action.GitThreadCacheDestroyFilter.doFilter(GitThreadCacheDestroyFilter.java:35)
... 18 filtered
at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:76)
... 1 filtered
at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:74)
... 38 filtered
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.lambda$invokeFilterChain$0(CustomerContextSettingFilter.java:181)
at com.atlassian.servicedesk.internal.utils.context.ReentrantThreadLocalBasedCodeContext.rteInvoke(ReentrantThreadLocalBasedCodeContext.java:142)
at com.atlassian.servicedesk.internal.utils.context.ReentrantThreadLocalBasedCodeContext.runOutOfContext(ReentrantThreadLocalBasedCodeContext.java:94)
at com.atlassian.servicedesk.internal.utils.context.CustomerContextServiceImpl.runOutOfCustomerContext(CustomerContextServiceImpl.java:64)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.outOfCustomerContext(CustomerContextSettingFilter.java:174)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilterImpl(CustomerContextSettingFilter.java:130)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilter(CustomerContextSettingFilter.java:121)
... 4 filtered
at com.atlassian.jwt.internal.servlet.JwtAuthFilter.doFilter(JwtAuthFilter.java:32)
... 8 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 4 filtered
at com.atlassian.web.servlet.plugin.LocationCleanerFilter.doFilter(LocationCleanerFilter.java:36)
... 49 filtered
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.sql.SQLException: Unexpected exception encountered during query.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2584)
at org.apache.commons.dbcp2.DelegatingConnection.setAutoCommit(DelegatingConnection.java:540)
at org.apache.commons.dbcp2.DelegatingConnection.setAutoCommit(DelegatingConnection.java:540)
at org.ofbiz.core.entity.jdbc.interceptors.connection.DelegatingConnection.setAutoCommit(DelegatingConnection.java:56)
... 3 filtered
at java.lang.reflect.Method.invoke(Method.java:498)
at net.java.ao.DelegateConnectionHandler.delegate(DelegateConnectionHandler.java:79)
at net.java.ao.DelegateConnectionHandler.invoke(DelegateConnectionHandler.java:54)
at com.sun.proxy.$Proxy3607.setAutoCommit(Unknown Source)
... 2 filtered
at java.lang.reflect.Method.invoke(Method.java:498)
at com.atlassian.activeobjects.spi.ConnectionHandler.delegate(ConnectionHandler.java:38)
at com.atlassian.activeobjects.spi.ConnectionHandler.invoke(ConnectionHandler.java:33)
at com.sun.proxy.$Proxy3965.setAutoCommit(Unknown Source)
at com.atlassian.dbexporter.jdbc.JdbcUtils.withNoAutoCommit(JdbcUtils.java:54)
... 277 more
Caused by: java.lang.ArrayIndexOutOfBoundsException: 500349
at com.mysql.jdbc.Buffer.readFieldLength(Buffer.java:273)
at com.mysql.jdbc.Buffer.fastSkipLenString(Buffer.java:156)
at com.mysql.jdbc.MysqlIO.unpackField(MysqlIO.java:684)
at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:416)
at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:3040)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2681)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2547)
... 295 more