--- src/core/org/apache/jmeter/resources/messages.properties	(Revision 1836855)
+++ src/core/org/apache/jmeter/resources/messages.properties	(Arbeitskopie)
@@ -803,7 +803,7 @@ 
 proxy_daemon_error_read_args=Could not add read arguments from clipboard\:
 proxy_daemon_msg_check_details=Please check the details below when installing the certificate in the browser
 proxy_daemon_msg_created_in_bin=created in JMeter bin directory
-proxy_daemon_msg_check_expiration=Certificate has a duration validity of {0} days, <br>if the created one (see below) is newer than the last one you installed, <br>ensure you remove the old one and install the new one.
+proxy_daemon_msg_check_expiration=<p>Certificate has a duration validity of {0} days, <br>if the created one (see below) is newer than the last one you installed, <br>ensure you remove the old one and install the new one.</p><p>The duration can be configured by setting the property <tt>proxy.cert.validity</tt>.</p>
 proxy_daemon_msg_install_as_in_doc=You can install it following instructions in <i>Component Reference</i> documentation <br>See <i>Installing the JMeter CA certificate for HTTPS recording</i> paragraph.
 proxy_daemon_msg_rootca_cert=Root CA certificate
 proxy_domains=HTTPS Domains\:
--- src/protocol/http/org/apache/jmeter/protocol/http/proxy/gui/ProxyControlGui.java	(Revision 1836855)
+++ src/protocol/http/org/apache/jmeter/protocol/http/proxy/gui/ProxyControlGui.java	(Arbeitskopie)
@@ -614,7 +614,7 @@ 
 
                 // Make dialog disappear after 7 seconds
                 JLabel messageLabel = new JLabel(sb.toString());
-                Timer timer = new Timer(7000, evt -> {
+                Timer timer = new Timer(60000, evt -> {
                     Window window = SwingUtilities.getWindowAncestor(messageLabel);
                     // Window may be closed by user
                     if(window != null) {
@@ -623,12 +623,14 @@ 
                 });
                 timer.setRepeats(false);
                 timer.start();
-                JOptionPane.showMessageDialog(this,
+                Object[] options = {"Understood"};
+                JOptionPane.showOptionDialog(this,
                         messageLabel,
                     JMeterUtils.getResString("proxy_daemon_msg_rootca_cert") + SPACE // $NON-NLS-1$
                     + KeyToolUtils.ROOT_CACERT_CRT_PFX + SPACE
                     + JMeterUtils.getResString("proxy_daemon_msg_created_in_bin"), // $NON-NLS-1$
-                    JOptionPane.INFORMATION_MESSAGE);
+                    JOptionPane.INFORMATION_MESSAGE,
+                    JOptionPane.DEFAULT_OPTION, null, options, options[0]);
             }
             return true;
         } catch (InvalidVariableException e) {