Unfortunately, it still does not work :/

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Thanks for you quick answer @eskimo :) It is always a pleasure to see your answers. I fixed app group mismatch: https://github.com/tony-go/NetworkMonitor/tree/sma-app-service But I have the same errors ... It seems that the agent is not started properly. I'll probably explore cs.github.com and see if I could find an macOS project that starts an agent with SMAppService.

For instance I noticed that I use BundleProgram in the Agent plist and before I used: Program

Did not resolve the issue :) haha

I think i should focus more on this error: Unable to register Error Domain=SMAppServiceErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedFailureReason=Operation not permitted}

For instance I took a look at this project that uses : https://github.com/zeek/zeek-agent-v2/blob/af61c534f6287438c923a0296d3225783f16017a/src/platform/darwin/ZeekAgent.app/Info.plist.agent.in#L27-L28 It uses the app identifier: https://github.com/zeek/zeek-agent-v2/blob/af61c534f6287438c923a0296d3225783f16017a/src/platform/darwin/ZeekAgent.app/entitlements.plist.agent#L5-L6 Note that I tried both: tonygo.TestES tonygo.TestES.Extension

I aslo tried to remove sandbox for the GUI, but it don't resolve the issue, so I guess it answer the question: But what about the GUI application? It is sandboxed right?