Mathcad Prime 2.0 help doesn't work

Hi. I think that your clear mind help me:). My system is Windows 8.1. One time I have noticed that help for MathCAD Prime 2.0 doesn't work. Program just gave me message (see bellow). How to fix it? Reinstallation doesn't help.

HTTP ERROR: 500

INTERNAL_SERVER_ERROR

RequestURI=/index.jspx

Caused by:

java.lang.NullPointerException

          at java.io.File.(Unknown Source)

          at com.arbortext.dmc.consumer.tool.Utils.getConsumerUserHome(Utils.java:16)

          at com.arbortext.dmc.consumer.update.UpdateManager.(UpdateManager.java:111)

          at com.arbortext.dmc.consumer.update.UpdateManager.getUpdateManager(UpdateManager.java:98)

          at com.arbortext.dmc.consumer.servletfilter.RedirectFilter.doFilter(RedirectFilter.java:86)

          at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1088)

          at com.arbortext.dmc.consumer.servletfilter.AuthenticationFilter.doFilter(AuthenticationFilter.java:76)

          at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1088)

          at com.arbortext.dmc.consumer.servletfilter.InitFilter.doFilter(InitFilter.java:149)

          at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1088)

          at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)

          at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)

          at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)

          at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)

          at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)

          at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)

          at org.mortbay.jetty.Server.handle(Server.java:324)

          at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)

          at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:829)

          at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:513)

          at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)

          at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)

          at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)

          at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)