title: JNLP "JVM Shared, not allowed to set security manager" error
body: <p>I have a JAVA Applet to perform digital signatures, certificate validations, and so on. It's signed with a valid certificate, it has a correct Manifest (I suppose) with values as:</p>
  
  <pre><code>Permissions: all-permissions
  Specification-Title: Applet Certificados digitales
  Specification-Version: v1.3
  Specification-Vendor: mycompany
  Application-Name: Applet Java mycompany
  </code></pre>
  
  <p>And, it works perfectly, into a "applet" tag, thanks to NPAPI friendly browsers (tested only on Firefox and IExplorer). It has been running so by years ...</p>
  
  <p>Now I want to let Chrome and Edge users use it, by using JNLP. 
  And here it's ALMOST ok. I say "almost" because I can read store certificates, access to my ASP.NET WebApi, perform digital signatures .... but now I can't open smart cards to read certificates, due that SecurityException when I set the security manager:</p>
  
  <pre><code>  public SmartCardProvider_SecurityManager(final ApduConnection conn) {
      super(NAME, VERSION, INFO);
      defaultConnection = conn;
  
      AccessController.doPrivileged(new PrivilegedAction&lt;Void&gt;() {
          @Override
          public Void run() {
              if (!(System.getSecurityManager() instanceof SmartCardProvider_SecurityManager)) {
                      System.setSecurityManager(new SmartCardProvider_SecurityManager(System.getSecurityManager()));
                     // Exception -&gt; JVM Shared, not allowed to set security manager
              }
  .... 
  </code></pre>
  
  <p>Where</p>
  
  <pre><code>private static final class SmartCardProvider_SecurityManager 
       extends SecurityManager { .....
  </code></pre>
  
  <p>This is my JNLP:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; 
   &lt;jnlp spec="1.0+" codebase="" href="thefile.JNLP"&gt;
   &lt;information&gt;
     &lt;title&gt;mycompany - JAVA apps&lt;/title&gt;
     &lt;vendor&gt;mycompany&lt;/vendor&gt;
     &lt;homepage href="http:\\www.mycompany.com" /&gt;
     &lt;description&gt;the description&lt;/description&gt;
   &lt;/information&gt;
   &lt;security&gt;
     &lt;all-permissions/&gt;
   &lt;/security&gt;
   &lt;resources&gt;
     &lt;j2se version="1.7+" href="http://java.sun.com/products/autodl/j2se"/&gt;
     &lt;jar href="APPLET_NAME.jar" main="false"  /&gt;
   &lt;/resources&gt;
   &lt;applet-desc documentBase="" 
      name="the_name" 
        main-class="myjavanamespace.clsApplet" 
        width="450" 
        height="250"&gt; 
      &lt;param name="0123225223   ..... /&gt; some ciphred params ... 
      &lt;param name="permissions" value="all-permissions" /&gt; 
  &lt;/applet-desc&gt;
  </code></pre>
  
  <p></p>
  
  <p>My last try was to add this param:</p>
  
  <pre><code>&lt;param name="separate_jvm" value="true"/&gt;
  </code></pre>
  
  <p>But I get the same exception. I am out of ideas, so any help will be appreciated.</p>
  
  <p>Current run enviroment:</p>
  
  <ul>
  <li><p>Java Plugin 11.72.2.15</p></li>
  <li><p>Using JRE 1.8.0_72-b15 Java HotSpot(TM) 64-Bit Server VM</p></li>
  </ul>