Actually, I found an error now. The admin console returns a completely white page. Here's the stacktrace from Xeams.log

Stacktrace:
org.apache.jasper.JasperException: Unable to compile class for JSP:

An error occurred at line: [386] in the jsp file: [/NewPageHeader.jsp]
The method isOnPremise() is undefined for the type ResourceBean
383: <li><A href="<%= response.encodeURL("FrontController?operation=tmpe4u") %>">Manage Temporary Emails</A></li>384:
385: <%
386: if(ResourceBean.isOnPremise()){
387: %>
388: <li><A href="<%= response.encodeURL("FrontController?operation=e2eenc") %>">End-To-End Encryption</A></li>
389: <li><A href="<%= response.encodeURL("FrontController?operation=240") %>">Import Wizard</A></li>

Stacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:213)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:520)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:397)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:367)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:351)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:605)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:399)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:379)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:327)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:779)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:711)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:459)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:385)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:313)
at com.synametrics.xeams.webfront.servlet.helper.V.K(Worker.java:125)
at com.synametrics.xeams.webfront.servlet.helper.U.K(AdminWorker.java:4215)
at com.synametrics.xeams.webfront.servlet.helper.U.ta(AdminWorker.java:13787)
at com.synametrics.xeams.webfront.servlet.helper.U.A(AdminWorker.java:12751)
at com.synametrics.xeams.webfront.servlet.helper.U.k(AdminWorker.java:12529)
at com.synametrics.xeams.webfront.servlet.FrontController.handleRequest(FrontController.java:286)
at com.synametrics.xeams.webfront.servlet.FrontController.doGet(FrontController.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:670)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:779)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at com.synametrics.xeams.filter.SynaFilter.doFilter(SynaFilter.java:58)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)