The digital signature is not trusted. Java will not allow any access to this application

I have a Java Web Start application, which I've tested on Windows 7, Linux and Mac OS X 10.7 (works fine on all).

On Mac OS X 10.8 Mountain Lion the following error occurs, with no option to choose "Allow".

The error looks like this:

Does anyone know of a workaround for this?

How do I change Java security settings on Mac?

On a Mac running OS X:Click Java. Click the Security tab. Move the Security slider down to Medium and click OK. The applets on my pages should now run.

Which Java is used for digital signature?

In Java, JDK Security API is used to create and implement digital signatures.

Just found a solution: Go into System prefs -> security and privacy, and check the box that allows applications to be downloaded from anywhere (you might have to click the lock to make changes to this)