You need the file NPSWF32_32_0_0_465.dll (for 32-bit Basilisk – the only version that supports Flash).
The key phrase "Basilisk Portable with Flash Player" usually refers to a specific distribution of the browser that comes pre-bundled with a clean, pre-activated version of the Flash player.
In the past, users had to hunt for NPSWF32.dll files and drag them into plugin folders. Today, portable distributions are configured to: basilisk portable with flash player
Q: Basilisk says "Flash plugin is vulnerable" and blocks it.
Q: .SWF files open but no sound.
Q: Mouse clicks don’t register in game.
Q: Can I run Basilisk Portable on macOS? You need the file NPSWF32_32_0_0_465
Q: How do I uninstall?
Below is a complete walkthrough for Windows. (Basilisk Portable also works on Linux via Wine, but Windows is the primary target.) Q: Mouse clicks don’t register in game