Authentication Failed after an AEM 6.3 upgrade

I am doing upgrade from AEM 6.1 author with mongodb to AEM 6.3 author.

     Step 1: pre upgrade task is done

     Step 2: Replaced AEM 6.1 jar with AEM 6.3 jar alone parallel AEM 6.1 crx instance

     Step 3: Unpacked AEM 6.3 jar with runmode mongo and it shows

                  - Build number changed, running in upgrade mode

                  - UpgradeUtil.handleInstallAndUpgrade has mode UPGRADE

     Step 4: Started the AEM 6.3 jar

Instance started with upgrade mode finally its got started but not able to login. The below error is throwing.

11.11.2017 18:25:23.190 *ERROR* [0:0:0:0:0:0:0:1 [1510404923182] GET /libs/granite/core/content/login.html HTTP/1.1] com.day.cq.auth.impl.LoginSelectorHandler requestCredentials: Abort login due to apparent misconfiguration.

11.11.2017 18:25:23.190 *ERROR* [0:0:0:0:0:0:0:1 [1510404923182] GET /libs/granite/core/content/login.html HTTP/1.1] com.day.cq.auth.impl.LoginSelectorHandler requestCredentials: Possible reasons: login page not existing or not accessible

11.11.2017 18:25:23.592 *ERROR* [qtp316797819-2676] com.day.crx.delite.impl.servlets.InitServlet Error while retrieving infos

java.lang.NullPointerException: null

    at com.day.crx.delite.impl.servlets.InitServlet.getFormattedName(InitServlet.java:126)

    at com.day.crx.delite.impl.servlets.InitServlet.doService(InitServlet.java:84)

    at com.day.crx.delite.impl.AbstractServlet.service(AbstractServlet.java:52)

    at com.day.crx.delite.impl.MainServlet.doService(MainServlet.java:129)

    at com.day.crx.delite.impl.MainServlet.service(MainServlet.java:107)

    at org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHandler.java:85)

    at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:79)

    at com.adobe.granite.license.impl.LicenseCheckFilter.doFilter(LicenseCheckFilter.java:308)

    at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:135)

    at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:74)

    at org.apache.felix.http.sslfilter.internal.SslFilter.doFilter(SslFilter.java:96)

    at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:135)

    at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:74)

    at org.apache.sling.security.impl.ReferrerFilter.doFilter(ReferrerFilter.java:295)

    at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:135)

    at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:74)

    at org.apache.sling.i18n.impl.I18NFilter.doFilter(I18NFilter.java:138)

    at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:135)

    at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:74)

    at org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.java:128)

    at org.apache.felix.http.base.internal.dispatch.DispatcherServlet.service(DispatcherServlet.java:49)

    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)

    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)

    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)

    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)

    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)

    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)

    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)

    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)

    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)

    at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215)

    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)

    at org.eclipse.jetty.server.Server.handle(Server.java:499)

    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)

    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)

    at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)

    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)

    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)

    at java.lang.Thread.run(Thread.java:745)