Since the release of Java 7 Update 51, users of older versions of the Java plug-in (like Java 7 Update 45) get the error message:
 
   
This browser has no Java Runtime Environment (JRE). 
Dimensions Web client needs JRE 1.5 or later. Please click on this link to download and install a Java Plug-in.

This browser has no Java Runtime Environment (JRE). 
Dimensions Admin Console needs JRE 1.5 or later. Please click on this link to download and install a Java Plug-in.

when attempting to access Web client or Adminconsole
 
This is caused by logic inside all Java plug-ins released as of Java 7 Update 25 that checks if Java updates are available, and blocks a vital mechanism needed by Dimensions, if such an update was found. Quoting from http://java.com/en/download/faq/release_changes.xml:
 

Web client or Adminconsole Java functionality will be  blocked under Some Conditions

Web client or Adminconsole calls from JavaScript to Java API are blocked when the Java Control Panel security slider is set to Very High level, or when the slider is at the default High level and the JRE has either expired or is below the security baseline.

 The moment the JRE detects that a newer version is available, which it does by checking Oracle's website, it will disable Java functionality on the older, currently installed JRE.

 (This can be confirmed by looking at the Java console with tracing enabled. There you will see:
 
network: Created version ID: 1.7.0.45
 network: Created version ID: 1.7.0.51
 security: LiveConnect (JavaScript) blocked due to security settings.

 
where 1.7.0.45 is an example of the currently installed JRE and 1.7.0.51 is the newer version that the JRE found on the Internet.)

Current tests indicate that 12.2.2.4 is compatible with the newer JRE, however previous versions do not appear to be compatible, so the newer JRE is not an option.