The Java 7 Update 51 (1.7.0_51) can result in SciFinder’s Java-based CAS Structure Editor failing to load or start.
Failure is due to this Java update now blocking all Java-based applications from working unless you specifically add (whitelist) a site to the Exception Site List.
Follow these basic instructions to add SciFinder to the Exception Site List. The instructions apply to Windows based systems and to Mac OS X 10.7.3 and newer.
1. Open the Java Control Panel (Control Panel -> Java on a Windows computer; System Preferences -> Java on a Mac)
2. Go to the Security tab and click the Edit Site List button
3. Add https://scifinder.cas.org
4. Click OK
5. Restart your browser, sign in to SciFinder, and open the Java-based structure editor again.
Note: Lowering the Security Level from High to Medium in the Java Control Panel should allow all Java applets to work, but CAS recommends using the Exception Site List method so you can control which applets will run.
If problems persist after making these changes please contact the CAS Customer Center.
More information from java.com