Error message from /opt/opennms/logs/daemon/output.log.
file: /opt/opennms/etc/datacollection-config.xml

<?xml version="1.0"?>
<datacollection-config rrdRepository="/opt/opennms/share/rrd/snmp/">

<snmp-collection name="default" snmpStorageFlag="all">
<rrd step="300">
<rra>RRA:AVERAGE:0.5:1:2016</rra>
<rra>RRA:AVERAGE:0.5:12:1488</rra>
<rra>RRA:AVERAGE:0.5:288:366</rra>
<rra>RRA:MAX:0.5:288:366</rra>
<rra>RRA:MIN:0.5:288:366</rra>
</rrd>

<resourceType name="procIndex" label="Process Table Index (UCD-SNMP MIB)"
resourceLabel="${prNames} (index ${index})">
<persistenceSelectorStrategy class="org.opennms.netmgt.collectd.PersistAllSelectorStrategy"/>
<storageStrategy class="org.opennms.netmgt.dao.support.IndexStorageStrategy"/>
</resourceType>

<groups>
<group name="net-snmp-proc" ifType="all">
<mibObj oid=".1.3.6.1.4.1.2021.2.1.1" instance="procIndex" alias="prIndex" type="integer" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.2" instance="procIndex" alias="prNames" type="string" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.3" instance="procIndex" alias="prMin" type="gauge" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.4" instance="procIndex" alias="prMax" type="gauge" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.5" instance="procIndex" alias="prCount" type="gauge" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.100" instance="procIndex" alias="prErrorFlag" type="integer" />
<mibObj oid=".1.3.6.1.4.1.2021.2.1.101" instance="procIndex" alias="prErrMessage" type="string" />
</group>
</groups>

<systems>
<systemDef name="Net-SNMP (UCD)">
<sysoidMask>.1.3.6.1.4.1.9.1.</sysoidMask>
<collect>
<includeGroup>net-snmp-proc</includeGroup>
</collect>
</systemDef>
</systems>
<include-collection dataCollectionGroup="MIB2"/>
<include-collection dataCollectionGroup="3Com"/>
<include-collection dataCollectionGroup="Acme Packet"/>
<include-collection dataCollectionGroup="AKCP sensorProbe"/>
<include-collection dataCollectionGroup="Alvarion"/>
<include-collection dataCollectionGroup="APC"/>
<include-collection dataCollectionGroup="Ascend"/>
<include-collection dataCollectionGroup="Asterisk"/>
<include-collection dataCollectionGroup="Bluecat"/>
<include-collection dataCollectionGroup="Bluecoat"/>
<include-collection dataCollectionGroup="Brocade"/>
<include-collection dataCollectionGroup="Checkpoint"/>
<include-collection dataCollectionGroup="Cisco"/>
<include-collection dataCollectionGroup="Cisco Nexus"/>
<include-collection dataCollectionGroup="CLAVISTER"/>
<include-collection dataCollectionGroup="Colubris"/>
<include-collection dataCollectionGroup="Concord"/>
<include-collection dataCollectionGroup="Cyclades"/>
<include-collection dataCollectionGroup="Dell"/>
<include-collection dataCollectionGroup="Ericsson"/>
<include-collection dataCollectionGroup="Equallogic"/>
<include-collection dataCollectionGroup="Extreme Networks"/>
<include-collection dataCollectionGroup="F5"/>
<include-collection dataCollectionGroup="Fortinet"/>
<include-collection dataCollectionGroup="Force10"/>
<include-collection dataCollectionGroup="Foundry Networks"/>
<include-collection dataCollectionGroup="HP"/>
<include-collection dataCollectionGroup="HWg"/>
<include-collection dataCollectionGroup="IBM"/>
<include-collection dataCollectionGroup="IP Unity"/>
<include-collection dataCollectionGroup="Juniper"/>
<include-collection dataCollectionGroup="Kyocera"/>
<include-collection dataCollectionGroup="Lexmark"/>
<include-collection dataCollectionGroup="Liebert"/>
<include-collection dataCollectionGroup="Makelsan"/>
<include-collection dataCollectionGroup="MGE"/>
<include-collection dataCollectionGroup="Microsoft"/>
<include-collection dataCollectionGroup="Mikrotik"/>
<include-collection dataCollectionGroup="Network Appliance"/>
<include-collection dataCollectionGroup="Netbotz"/>
<include-collection dataCollectionGroup="NetEnforcer"/>
<include-collection dataCollectionGroup="Netscaler"/>
<include-collection dataCollectionGroup="Net-SNMP"/>
<include-collection dataCollectionGroup="Nortel"/>
<include-collection dataCollectionGroup="Novell"/>
<include-collection dataCollectionGroup="pfSense"/>
<include-collection dataCollectionGroup="Powerware"/>
<include-collection dataCollectionGroup="PostgreSQL-JDBC"/>
<include-collection dataCollectionGroup="Riverbed"/>
<include-collection dataCollectionGroup="Savin or Ricoh Printers"/>
<include-collection dataCollectionGroup="ServerTech"/>
<include-collection dataCollectionGroup="SofaWare"/>
<include-collection dataCollectionGroup="SUN Microsystems"/>
<include-collection dataCollectionGroup="Trango"/>
<include-collection dataCollectionGroup="WMI"/>
<include-collection dataCollectionGroup="XMP"/>
<include-collection dataCollectionGroup="Zeus"/>
<include-collection dataCollectionGroup="VMware3"/>
<include-collection dataCollectionGroup="VMware4"/>
<include-collection dataCollectionGroup="VMware5"/>
<include-collection dataCollectionGroup="VMware-Cim"/>

</snmp-collection>
<!-- We need a dedicated collection with a different RRD setup for EJN equipment because
the data in the EJN SNMP MIB is only updated once every 15 min by default or alternatively
once every 3 min with the hidden "set services epg pgw snmp update-every-three-minutes"
config option -->
<snmp-collection name="ejn" snmpStorageFlag="select">
<rrd step="180">
<rra>RRA:AVERAGE:0.5:1:3360</rra>
<rra>RRA:AVERAGE:0.5:20:1488</rra>
<rra>RRA:AVERAGE:0.5:480:366</rra>
<rra>RRA:MAX:0.5:480:366</rra>
<rra>RRA:MIN:0.5:480:366</rra>
</rrd>

<include-collection dataCollectionGroup="ejn"/>
</snmp-collection>
</datacollection-config>

Could anyone please tell me what is the problem within the "include-collection"? Because when I deleted all content of it the error message just turn to "ValidationException:element "page-sequence"occurs more than once".

Please help.