Dear Kevin, Your guidance has resolved the issues I was facing. By replacing kextload with kmutil, the KEXT loads into the system successfully, eliminating the instability issues I encountered previously. Now I can accurately trace its execution flow by the log. Additionally, I noticed that if I remove the device ID from Info.plist, the KEXT no longer loads into the system. Is this the expected behavior? Best regards, Charles

Thank you very much!

fredapp NewUserClient() Start fredapp NewUserClient() - Failed to create UserClientProperties with error: 0xe00002c2. fredapp NewUserClient() End When I try to connect to dext, I got this error log. Where and how to set the value kIOPCIDeviceConnectType in dext?