• Why do I need administrator privileges to install Java Web Start on Windows?
• What is the "Security Warning" that comes up the first time I run the application?
• Why do I get an error about "Cannot load flightpath.jar" using the latest Java 1.5.0?
• Why does Java Web Start say the jar file is corrupted?
• Why can't I start the Flight Path Tool in my browser?
• What kind of hardware is required to run this tool?

Why do I need administrator privileges to install Java Web Start on Windows?
Java Web Start needs to register the MIME type of its launch file with the system registry. MIME types are mappings used to find the correct application to handle particular file types. MIME stands for "Multipurpose Internet Mail Extensions." It is a standard across the internet.
   Java Web Start's MIME entry identifies it as the application to launch to handle Java Web Start applications like the Flight Path Tool. The MIME type applies whenever you try to open or browse to a file with the ".jnlp" extension which identifies itself as an "application/x-java-jnlp-file."

What is the "Security Warning" that comes up the first time I run the application?
There are several features of the Flight Path Tool which require access to your system and network. To print, the Flight Path Tool needs access to your local printer. To save and reload preferences, the Flight Path Tool needs access to your local disk drive. To get its data, the Flight Path Tool needs to make an outgoing connection across your network to our data server. These are the kinds of things applications do all of the time without warning you.
   To ensure that you are downloading the real Flight Path Tool, and not a malicious application, the executable files are signed to authenticate them. The warning is Java Web Start's way of telling you that you are downloading an application that requires access to your system, and asking you to verify the application is coming from where you expect it.

Why do I get an error about "Cannot load flightpath.jar" using the latest Java 1.5.0?
There is a bug in the initial release of Java Web Start for Java 1.5.0 (#5057141). The bug prevents applications from downloading properly. The message window that appears says "Unable to download flightpath.jar." The Details of the error will reveal an exception of the type:
JNLPException[category: Download Error : Exception: java.io.IOException: Stream closed. : LaunchDesc: null ]
   Unfortunately, there is no workaround to this bug. It has, however, been fixed by Sun and is scheduled to be included in build 58 of Java 1.5.0. If you are experiencing this error, please install the last stable release of Java (1.4.2). It does not contain the bug.

Why does Java Web Start say the jar file is corrupted?
Some web filtering products used on Microsoft Windows, such as NetNanny and certain firewall programs, corrupt the digital signatures on downloaded application files. This makes the downloaded files appear to have been tampered with. For security reasons, Java Web Start then refuses to run the downloaded application. The only solution is to turn off the offending software, clear your Java Web Start cache, and re-launch the Flight Path Tool application.

Why can't I start the Flight Path Tool in my browser?
Besides various flavors of Linux, the Flight Path Tool Application has only been tested on Windows XP running Internet Explorer 6.0. We cannot guarantee the application will start on all combinations of OSs and browsers, and, because of our security policy, we are not allowed to run many of the combinations our users have installed (for example, Win98).
   However, it is not necessary to use a browser to run the Flight Path Tool! A browser is used only to locate the Flight Path Tool, and to kick off Java Web Start. To run the Flight Path Tool without a browser, download and install Java Web Start, then once you have Java Web Start running, type the following URL into the Java Web Start "Location" field:   https://www.aviationweather.gov/static/adds/java/fpt/fpt.jnlp

What kind of hardware is required to run this tool?
Generally, we suggest a minimum of 500 MHz processor and 500 MB RAM along with 1024x768 monitor setting. If using a 28.8 or 56K modem internet connection, then expect the application (6.8 MB) to take up to 40 minutes to download the first time. Once downloaded, it does not get downloaded again (until a new version is available). The response time of the application (accessing data) will vary according to your internet connection as well.