MWS User Default Not found Error

Hi All,
Any one familiar with the below error in MWS:
2020-12-05 00:00:55 EET (c.w.c.s.r.r.s.Axis1CommandServlet:ERROR) [qtp1447204617-282629][[WS:606790]] [[WS:606790]] - [POP.017.0028] User Default not found
com.webMethods.portal.bizPolicy.BizException: [POP.017.0028] User Default not found
at com.webMethods.portal.bizPolicy.command.task.webservice.AbstractTaskCommand.handle(AbstractTaskCommand.java:51) ~[com.webMethods.mws.server.taskengine_10.5.0
.0008-0111.jar:10.5.0.0008-0111]
at com.webMethods.caf.server.remote.rpcws.servlet.Axis1CommandServlet.doPost(Axis1CommandServlet.java:441) [com.softwareag.web.caf.mws.server.remote.rpcws_10.5.
0.0008-0111.jar:10.5.0.0008-0111]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) [javax.servlet-api_3.1.0.jar:3.1.0]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) [javax.servlet-api_3.1.0.jar:3.1.0]
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:808) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at com.softwareag.platform.wab.filter.saml.SAMLAssertionFilter.handleValidSession(SAMLAssertionFilter.java:510) [com.softwareag.platform.wab.filter.saml_10.5.0.
0000-0444.jar:10.5.0.0000-0444]
at com.softwareag.platform.wab.filter.saml.SAMLAssertionFilter.doFilter(SAMLAssertionFilter.java:250) [com.softwareag.platform.wab.filter.saml_10.5.0.0000-0444.
jar:10.5.0.0000-0444]
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:259) [org.eclipse.jetty.servlets_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:222) [org.eclipse.jetty.servlets_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577) [org.eclipse.jetty.security_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515) [org.eclipse.jetty.servlet_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v2015
0224]
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at com.webMethods.portal.webapp.jetty7.MwsServer.handle(MwsServer.java:100) [com.webMethods.caf.server_10.5.0.0008-0111.jar:10.5.0.0008-0111]
at org.eclipse.jetty.server.Server.handle(Server.java:497) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:310) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257) [org.eclipse.jetty.server_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540) [org.eclipse.jetty.io_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635) [org.eclipse.jetty.util_9.2.9.v20150224.jar:9.2.9.v20150224]
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555) [org.eclipse.jetty.util_9.2.9.v20150224.jar:9.2.9.v20150224]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_222]
Caused by: com.webMethods.portal.PortalException: [POP.017.0028] User Default not found
at com.webMethods.portal.bizPolicy.command.task.BaseTaskCommand.getPrincipal(BaseTaskCommand.java:65) ~[com.webMethods.mws.server.taskengine_10.5.0.0008-0111.ja
r:10.5.0.0008-0111]
at com.webMethods.portal.bizPolicy.command.task.webservice.AbstractTaskCommand.handle(AbstractTaskCommand.java:41) ~[com.webMethods.mws.server.taskengine_10.5.0
.0008-0111.jar:10.5.0.0008-0111]
… 31 more

Taking a guess based on the error, have a look at the WmTaskClient configuration - sounds like you might have an ACL set for user impersonating that isn’t quite right.

See documentation here for a description:
Specifying a User Account for the WmTaskClient Package (softwareag.com)