title: java.lang.NullPointerException: while trying to invoke the method com.sap.isa.core.eai.BackendConfig.getId() of a null object
body: <p>I'm migrating a SAP B2B Commerce project from version 7.0 to 7.4, with the previous version of Java 1.4 to 1.7.</p>
  
  <p>I can't see the login page, instead i see this 500 Internal Server Error message:</p>
  
  <pre><code>Error: ISA Framework: javax.servlet.ServletException: java.lang.NullPointerException: while trying to invoke the method com.sap.isa.core.eai.BackendConfig.getId() of a null object loaded from local variable 'config'
  </code></pre>
  
  <p>But after a search in my files, I never see the variable 'config' or the com.sap.isa.core.eai.BackendConfig import.</p>
  
  <p>Where is the problem located? and how I can solve this issue?
   is this problem unrelated to my components?</p>
  
  <p><strong>UPDATE</strong></p>
  
  <pre><code>/usr/sap/CRP/DVEBMGS26/j2ee/cluster/apps/sap.com/home~icss_s7/servlet_jsp/icss_s7/work/JEE_jsp_user_logon_login_1509734170000.java:448: cannot find symbol
  symbol  : class Iterator
  location: class JEE_jsp_user_logon_login_1509734170000
                                  Iterator it = langTree.iterator();
  </code></pre>
  
  <p>Now the error message changed to this, I did change nothing all, just refreshed the page, at least I get five similar errors about not being able to find the class symbol. This can be easily be fixed to make the necessary imports but I had search for such class, and it's not in the project, not sure if this class <code>JEE_jsp_user_logon_login_1509734170000.java</code> is generated somewhere else, or is unrelated to my components.</p>