ENV: win7/x86/jre9-b144/IE11

Steps to reproduce:
1. Import self ca cert to JCP -> Security -> Manage Certificates -> Singer CA.
http://kgb.us.oracle.com:8080/FXWeeklySignedTest/lib/self.valid.cert
2. Edit java.security and change jdk.jar.disabledAlgorithms as the following (add 'DSA,'):
"jdk.jar.disabledAlgorithms=MD2, MD5, DSA, RSA keySize < 1024, \
      DSA keySize < 1024"
3. Load javafx applet that is signed with a "DSA" cert:
http://kgb.us.oracle.com:8080/FXWeeklySignedTest/html/testWeaklySigned.html
4. If fx app is blocked directly with message "JavaFX application could not launch due to system configuration(show error details)......" in applet area(fx-applet-1.png) and no blocked dialog shows up, this bug is reproduced. If you click on "show error details", the page will redirect to a page with "Runtime error. Click for details" on applet area(fx-applet-2.png). Click on "Runtime error.....", a dialog with title "Application Error" will show up(fx-applet-3.png).

Expected behavior:
A blocked dialog should show up directly after loading javafx applet from browser.

Note:
1. It works fine with javafx application: A dialog "Application Error" will show up after loading javafx application from browser(http://kgb.us.oracle.com:8080/FXWeeklySignedTest/html/testWeaklySigned_JNLP.html). See attachment fx-application.png
2. It's the same issue with JDK-8166444. JDK-8166444 is about revoked signed fx applet and it has been fixed. But the same issue happens for weakly signed fx applet.