Applet不适用于Java 7

In production env, we use an applet provided by a 3rd party vendor for 2FA login. We dont have any source code, have just the jar file. The applet basically encrypts the login info. Now it works well for most of the users, but few have problem with it using Java 7. It shows the message we put in the applet tag, which usually is being shown if browser doesn't support Java. How to fix the issue on our own (without 2FA team support) as we only hold the jar file? In production env, we use an applet provided by