If you get this message related to a Java application, in most cases it is blocked due to the changes made starting with Java 1.7.51 version concerning security.
As a work-around, you can lower the security settings from control panel – java or add exceptions to the links/applications that you use and see if they are blocked.
If this doesn’t work, there is another solution that is not recommended due to security risks but in some cases might be the only way to run an application, especially with self signed applications and a few more. Navigate to start – control panel – Java – advanced – CHECK the “Disable verification (not recommended)” checkbox from “Mixed code (sandboxed vs. trusted) security verification” and CHECK the “Do not check (not recommended)” checkbox from “Perform certificate revocation checks on”. Alternativelly, you can downgrade Java to a lower version than 1.7.51 for example 1.7.45 and so the previously blocked Java application should work.
Downgrading is also risky as older java versions don’t have stable security features either.