Whitelabel Error Page (OpenKM CE 7.0.2)

[kwokhy]

Hello,

When I try to check the "logged users" records, OpenKM shows "Whitelabel Error Page". I checked the "localhost" log file and the following messages were recorded:

org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [dispatcherServlet] in context with path [/openkm] threw exception [An exception occurred processing [WEB-INF/jsp/management/auth/loggedUsers/list.jsp] at line [147]

144: <td>${se.id}</td>
145: <td>${se.ip}</td>
146: <td>${se.host}</td>
147: <td><u:formatDate calendar="${se.creation}"/></td>
148: <td><u:formatDate calendar="${se.lastAccess}"/></td>
149: <td align="center">
150: <a href="${urlLog}" type="button" class="btn btn-sm btn-light p-1 ml-1">


Stacktrace:] with root cause
java.lang.NullPointerException
at java.base/java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:617)
at java.base/java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:599)
at com.openkm.util.tags.FormatDateTag.doStartTag(FormatDateTag.java:69)
at org.apache.jsp.WEB_002dINF.jsp.management.auth.loggedUsers.list_jsp._jspx_meth_u_005fformatDate_005f0(list_jsp.java:1727)
at org.apache.jsp.WEB_002dINF.jsp.management.auth.loggedUsers.list_jsp._jspx_meth_c_005fforEach_005f0(list_jsp.java:1558)
at org.apache.jsp.WEB_002dINF.jsp.management.auth.loggedUsers.list_jsp._jspService(list_jsp.java:291)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:349)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:300)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:623)
.........

OS: Ubuntu 24.04.4
Jave: OpenJDK 11.0.31
Browser: Firefox, Edge

Please give some suggestions to me for troubleshooting.
Thanks for your help