Since Upgrade to MR4 I can reproduce this error when doing any GUI Packet capture and clicking 28 (or some times a few more) times in a row on the refresh button.
only thing that helps then is logging in with SSH and executing:
service tomcat:restart -ds nosync

Any browser.

Userportal on other port still works when WebAdmin is generating the error 500.

Never noticed the issue in MR1 and used the packet capture option regularly there.
See logs:
tomcat.log
2021-01-11 12:58:05,954:INFO:CSC - EventBean: { opCode: manage_page_detail, mode: 301, waitForeResponse: true, reques tType: 1, opcodetype: 0, entityId: 39, beanName: null, syncalbe: true, comProtocol: u }
2021-01-11 12:58:06,483:ERROR: - EXCEPTION IN RESULTSET WRAPPER WHILE EXECUTING QUERY: java.lang.NullPointerException java.lang.NullPointerException
at com.elitecore.jdbchelper.ResultSetWrapper.<init>(ResultSetWrapper.java:40)
at com.elitecore.jdbchelper.SqlReader.getResultSetWrapper(SqlReader.java:199)
at com.sophos.sf.auth.AuthHelper.isRefererCheckRequired(AuthHelper.java:105)
at com.sophos.sf.auth.AuthHelper.hasValidReferer(AuthHelper.java:128)
at com.sophos.sf.auth.HttpSessionHelper.isExpired(HttpSessionHelper.java:59)
at com.sophos.sf.auth.HttpSessionHelper.isExpired(HttpSessionHelper.java:29)
at cyberoam.sessionmanagement.SessionCheckFilter.doFilter(SessionCheckFilter.java:69)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1602)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1701)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1668)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:220)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:502)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
at java.lang.Thread.run(Thread.java:748)
2021-01-11 12:58:06,483:INFO:CSC - EventBean: { opCode: manage_page_detail, mode: 301, waitForeResponse: true, reques tType: 1, opcodetype: 0, entityId: 39, beanName: null, syncalbe: true, comProtocol: u }
2021-01-11 12:58:06,483:ERROR: - EXCEPTION IN RESULTSET WRAPPER WHILE EXECUTING QUERY: java.lang.NullPointerException java.lang.NullPointerException
at com.elitecore.jdbchelper.ResultSetWrapper.<init>(ResultSetWrapper.java:40)
at com.elitecore.jdbchelper.SqlReader.getResultSetWrapper(SqlReader.java:199)
at com.sophos.sf.auth.AuthHelper.isRefererCheckRequired(AuthHelper.java:105)
at com.sophos.sf.auth.AuthHelper.hasValidReferer(AuthHelper.java:128)
at com.sophos.sf.auth.HttpSessionHelper.isExpired(HttpSessionHelper.java:59)
at com.sophos.sf.auth.HttpSessionHelper.isExpired(HttpSessionHelper.java:29)
at cyberoam.corporate.servlets.CyberoamCommonServlet._doPost(CyberoamCommonServlet.java:486)
at cyberoam.corporate.servlets.CyberoamCommonServlet.doPost(CyberoamCommonServlet.java:363)
at cyberoam.corporate.servlets.CyberoamCommonServlet.doGet(CyberoamCommonServlet.java:205)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:873)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1623)
at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:214)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
at cyberoam.utilities.csrf.CSRFCheckFilter.doFilter(CSRFCheckFilter.java:150)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
at cyberoam.sessionmanagement.SessionCheckFilter.doFilter(SessionCheckFilter.java:74)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1602)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1701)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1668)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:220)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:502)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
at java.lang.Thread.run(Thread.java:748)
2021-01-11 12:58:06,484:ERROR:ACL - Exception in checkUserOperation java.lang.NullPointerException
at com.elitecore.jdbchelper.SqlReader.getInstanceResultSetWrapperForPreparedStatement(SqlReader.java:806)
at com.elitecore.jdbchelper.SqlReader.getInstanceResultSetWrapperForPreparedStatement(SqlReader.java:686)
at cyberoam.system.helpers.ACLImplHelper.isPageReadable(ACLImplHelper.java:125)
at cyberoam.corporate.servlets.CyberoamCommonServlet._doPost(CyberoamCommonServlet.java:526)
at cyberoam.corporate.servlets.CyberoamCommonServlet.doPost(CyberoamCommonServlet.java:363)
at cyberoam.corporate.servlets.CyberoamCommonServlet.doGet(CyberoamCommonServlet.java:205)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:873)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1623)
at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:214)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
at cyberoam.utilities.csrf.CSRFCheckFilter.doFilter(CSRFCheckFilter.java:150)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
at cyberoam.sessionmanagement.SessionCheckFilter.doFilter(SessionCheckFilter.java:74)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1602)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1701)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1668)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:220)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:502)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
at java.lang.Thread.run(Thread.java:748)
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