Introduction
Running Java Web Start applications on MacOS is a little bit tricky. Apple has added some pretty restrictive things in place, which prevents it from being a simple thing.

This page will describe how to ease the pain a little bit, but be aware that following all these steps will slightly lower the level of security of your machine. Parts of this will be safer to do, but there will be a note where you change the default security level of the machine, and the concrete consequences of doing so.

Those of you who are somewhat security aware will realize it's not that big of a deal, but it's something you should make a decision on yourself.

The problem
FUMBBL / FFB uses what's called "Java Web Start" to download, install and launch the client. By default, MacOS will quarantine executable applications you download if they're not crytographically signed. This signing process is not possible for a JNLP file (which is effectively a text file), which causes a little bit of a dilemma when you try to launch the client.

Typically, you'll get a popup like this, giving you no way to start the application:



In earlier versions of MacOS, you could open your download folder, right-click the file and effectively force open the file. This has been removed in more recent versions.

Manual workaround
In order to force the file to be startable, you can do the following process:

1. Download the jnlp file
2. Try to open it (this will trigger the dialog shown above)
3. Click "Done" (leaving the file in the downloads folder
4. Open System Settings
5. Find "Privacy and Security" on the left
6. Scroll to near the bottom of the list
7. You will find a section like this:



8. Click "Open Anyway"
9. Go through any additional authentication it asks for

This will tell your OS that you trust the source of the file you just downloaded, and you want to launch it anyway.

Doing this is relatively safe, assuming you trust the source of the file (fumbbl.com in this case). You can do this manually for every JNLP file you download and maintain a fairly high level of security on your machine.

However, if you can't be bothered to click around a hundred times every time, we move on to the next section.

Quicker method
What's happening under the hood on the computer is that files that are downloaded are "flagged" on the OS level that they are potentially unsafe. Clicking the "Open Anyway" button is equivalent to removing this flag from the file and then launching it.

With this information at hand, we can make the above process quicker:

1. Download the jnlp file
2. Open the terminal
3. Navigate to your Downloads folder (typically "cd Downloads")
4. Enter the following command: xattr -c ffblive.jnlp (adjusting for the actual filename)
5. Go back to your browser, open the list of downloads and click the jnlp file

Less clicking, sure, but I'm hearing you say that you're not going to do terminal nonsense to play FFB, and you'll never remember that command anyway.

Fine, let's add some automation by going to the next section

Automated approach
Ok, now that we know what we need to do, we want to make it automatic so we can just configure this once and for all and be done with it.

MacOS comes with a tool called "Automator", which can do things precisely like this. It's a little bit of technical configuration to do, but you should only need to do this once.

Let's go:

1. Start the "Automator" application
2. Select File->New
3. It will ask for the type of document you want to create. Pick "Folder Action" and click the "Choose" button
4. Now you get a confusing panel with two columns of things on the left and a big empty panel in the middle telling you to drag actions or files into it.
5. At the top, in the "Folder Action receives files[...]" dropdown, change it to your Downloads folder
6. In the second column, search for the item called "Find Finder Items" and drag it into the central panel
7. This will show a new panel where you need to change some things:
8. Change the "Search" field to Downloads
9. Change the "Any content" to "File Extension"
10. In the text box after "contains", enter jnlp
11. Go back to the second column and find "Run Shell Script", dragging it into the central panel under the Find Finder Items panel you just configured
12. Now you'll see another set of options:
13. Leave Shell as-is, but change the "Pass input" dropdown to "as arguments"
14. The larger text box will change to some lengthy text, which you should just select and get rid of.
15. In its place, enter the following: /usr/bin/xattr -c $*
16. It should look something like this:



17. Go to the File menu, and select Save... Call it something reasonable that makes sense to you (such as Unquarantine JNLP) and click the save button
18. Quit Automator

Now when you go back to fumbbl.com and try to launch the client (for example trying to spectate a game), the process is a little bit easier:

1. Click the spectate link to download the jnlp
2. Keep an eye on the right side of the menu bar. You should see a small cog icon appear within a few seconds, and then disappear again
3. Once this has happened, you can click to launch the JNLP file

Security implications
Automating this process will remove a layer of protection for JNLP files that you download from the Internet. While it doesn't automatically actually execute anything, adding this automation will slightly reduce your level of security.

If you think that you are savvy enough to not launch untrusted JNLP files, the changes outlined here are fairly safe. In the end, however, it's up to you what you are comfortable with.