If the Java runtime is not installed, some issues that are known to occur include. Adobe recommends that corporate IT organizations pre install Java (or make sure that Java can be installed through their firewalls/security) to avoid conflicts with Adobe applications.

If you encounter any issues, install Java to correct the problems. If you do not install Java before running an Adobe application, there can be missing or improperly behaving features. At runtime, when you launch an Adobe application, you are prompted to install Java if it is not already installed.

Or it can be installed later before you install Adobe applications. Adobe and Apple have worked together to ensure that you can install Java at OS install time. Since current Adobe installers and applications were built before these changes by Apple, Adobe software anticipates that Java is installed. It is now an optional install that you must select. Apple recently changed the way it includes Java in Mac OS, and with Lion, Java is no longer preinstalled. Many Adobe applications depend on the Oracle Java Runtime Environment (JRE) for some features to work.

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