added to known limitations (#12071)

Author: bitsandfoxes

docs/platforms/unity/troubleshooting/img/unity-file-system-access-permissions.png

@@ -4,6 +4,12 @@ sidebar_order: 9000
 description: "Learn more about the Unity SDK's known limitations. "
 ---
 
+## File System Access Permissions
+
+![A popup requesting permissions to read from the `Downloads` folder](./img/unity-file-system-access-permissions.png)
+
+Starting with macOS Mojave (10.14), directories like `Desktop`, `Documents`, and `Downloads` are considered privacy-sensitive locations and are protected by the operating system's security sandbox. When running a Unity application from one of these locations, users might encounter a popup requesting access. This occurs because the default .NET `HttpMessageHandler` attempts to resolve domain names, which requires filesystem access. Note, that disallowing access to these locations does not affect the SDK from reporting errors.
+
 ## Stack Traces
 
 ### Line Numbers Missing On Button Click Events