Hi. Welcome.
I'm no longer a registered Apple developer, so the extractor is not signed to satisfy the restrictions in the current OS versions.
It's pretty ancient now, so I thought I'd better check it following your message. I downloaded it from the
version 2.0.0 link in the first post and it still seems to work OK.
In order to open an application created by an unregistered developer these days, you first need to make sure your preferences are set to allow it. To do that:
- Open System Preferences and select the Security and Privacy/General tab. Make sure that "Allow apps downloaded from:" is set to "App Store and identified developers". If it isn't, click the lock to make changes, and change to that setting. Close System Preferences.
Even then, you can't just double click an unregistered app to start it. MacOS will complain and refuse to open it. You need to
right click the extractor app icon and select Open. You should see a warning message. Confirm that you want to open it. You should then see the Macapaka File menu where you can choose to open a .fpk file. There's no window to see until you choose a .fpk file.
Let me know if this works for you.