Uninstall Applet failed to launch, it throws a java.io.IOException: Invalid public key

How to reproduce the issue:
- Use Windows 7 / x86-64 / German
- Install JDK 1.6.0_38 (32 bit)
- Install JDK 1.7.0_11 (32 bit)
- Go to http://java.com/uninstall-tool with Firefox 18.0.1
- Click on the Applet in order to start the Java Plug-in (Firefox has disabled 7u11 Java Plug-in by default)
- Click on the red button called "I Agree to The Terms and Want to Continue"
- The Java uninstall applet is loading, please be patient (see uninstall-waiting.png), it throws java.io.IOException: Invalid public key (see Java-Console output below)
- The browser tells the user that the applet failed (see uninstall-failed.png)
- Note also the last line of the Java-Console which tells the user: "Remove old Java versions removed"
- Note that nothing has been removed

Java-Console output:

Java-Plug-in 10.11.2.21
JRE-Version verwenden 1.7.0_11-b21 Java HotSpot(TM) Client VM
[--snip--]
basic: JNLP2ClassLoader.findClass: com.oracle.javauninstall.controller.JavaRemovalTool$25$1: try again ..
basic: JNLP2ClassLoader.findClass: com.oracle.javauninstall.util.ModuleExtractor: try again ..
basic: JNLP2ClassLoader.findClass: com.oracle.javauninstall.controller.InstalledVersionDetector: try again ..
JRT_NATIVE::Java Scrub Version::1.0.0-b02
JRT_NATIVE::SHOW_VERSION:: 1.6.0_38:32 1.7.0_11:32
basic: JNLP2ClassLoader.findClass: com.oracle.javaBaselineParser.JavaVersionXMLParser: try again ..
JRT_STATUS::Error in verifying public key::JRT_ACTION::Show fail to launch process panel
JRT_EXCEPTION::Invalid public key
java.io.IOException: Invalid public key
at com.oracle.javaBaselineParser.JavaVersionXMLParser.verifyPublicKey(JavaVersionXMLParser.java:113)
at com.oracle.javaBaselineParser.JavaVersionXMLParser.<init>(JavaVersionXMLParser.java:71)
at com.oracle.javaBaselineParser.JavaVersionXMLParser.getInstance(JavaVersionXMLParser.java:51)
at com.oracle.javauninstall.controller.JavaRemovalTool.verifySystemAndShowPanel(JavaRemovalTool.java:1399)
at com.oracle.javauninstall.controller.JavaRemovalTool$25$1.run(JavaRemovalTool.java:1651)
at java.lang.Thread.run(Unknown Source)
basic: JNLP2ClassLoader.findClass: com.oracle.javauninstall.controller.JavaRemovalTool$3: try again ..
IsSendingPing : true
basic: JNLP2ClassLoader.findClass: com.oracle.javauninstall.controller.Ping: try again ..
JRT_STATUS::Java scrub removed::JRT_ACTION::
JRT_STATUS::Remove old Java versions removed::JRT_ACTION::