Compatibility Notes
Operating Systems
Little Snitch 4 is designed and built to perfectly integrate into macOS, providing you with the best experience you’ve come to expect.
macOS Mojave
10.14
macOS Catalina
10.15
macOS Big Sur
11.0
Compatibility with macOS High Sierra
Requires Little Snitch 4.0.3 or newer
Installation
During the Installation process you may see a message: “System Extension Blocked”. This is part of a new security mechanism in High Sierra, requiring you to explicitly allow the installation of a third party system extension. To complete the installation of Little Snitch you have to allow loading the extension in System Preferences > Security & Privacy > General.
Little Snitch 5 (coming soon)
Some of the MacBook Pro models from mid 2010 have defective video RAM in their discrete graphics card. These computers have two graphics cards: one built-in to the CPU using standard system RAM and a separate discrete graphics processor (GPU) with dedicated video RAM. For each application, the operating system decides which of the two graphics cards is used.
Some operations in Little Snitch Network Monitor (especially the Map View) trigger a switch to the discrete graphics card. If defective RAM locations are touched this causes an operating system crash (kernel panic). You can distinguish this type of panic by looking at the panic log. It shows the graphics driver as the component initiating the panic.
Note that only a minority of the mid 2010 MacBook Pro models are affected. As far as we can tell, there is no way how Little Snitch Network Monitor could prevent the graphics engine switch.
If you are affected by this issue, do not open the Map View. Once the Map View has been opened, Network Monitor renders all graphics operations on the discrete graphics engine.