Java Plugin does not work in Firefox after installing Java 7 Update 10 and above

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Java plug-in does not work in Firefox after installing Java 7 Update 10 (7u10) and above.

This article applies to:

Browser(s): Firefox
Java version(s): 7.0

SYMPTOMS

Upon completing install of Java 7u10 and above, following error appears:

Error: A plug-in is needed to display this content. Install Plugin

CAUSE

This is due, as we have seen, to a conflict that Java 7u10 and above have with stand alone installations of JavaFX.
Example: If Java 7u5 and JavaFX 2.1.1 are installed and if Java is updated to 7u10, Firefox is unable to detect that Java 7u10 is installed.

SOLUTION

To resolve this issue it is recommended to uninstall all versions of Java and JavaFX before installing Java 7u10 and above.
Please follow the steps below for resolving this issue.

Remove all versions of Java and JavaFX through the Windows Uninstall Control Panel.
Instructions on uninstalling Java.
Run the Microsoft uninstall utility to repair corrupted registry keys that prevents programs from being completely uninstalled or blocking new installations and updates.
Download and install the Windows offline installer package.