the call stack * thread #40   frame #0: 0x00007ff815f6720a libsystem_kernel.dylib`__ulock_wait + 10   frame #1: 0x00007ff815fb62c5 libsystem_platform.dylib`_os_unfair_lock_lock_slow + 162  * frame #2: 0x00007ff816f82ffe Foundation`-[NSConcreteTask processIdentifier] + 28   frame #3: 0x00000001053e95e5 libqaxbase.macos.dylib`-[NSTask(self=0x0000600002261590, _cmd="waitUntilExitWithTimeout:sendTerm:sendKill:", TO=2, SENDTERM=YES, SENDKILL=YES) waitUntilExitWithTimeout:sendTerm:sendKill:] at os_base_api.mm:79:25   frame #4: 0x00000001053ea84a libqaxbase.macos.dylib`OSBaseApi::ExecCmd(this=0x0000600002cb5700, cmdWithArgs="netstat -rn | awk '/default/ {if ( index($4, \"llw0\") > 0 ){print $2} }'", result=0x0000600000df0930) at os_base_api.mm:278:5   frame #5: 0x000000010557ed77 libnacplugin.dylib`NacPlugin::Exec(this=0x00007f795df04150, cmd="netstat -rn | awk '/default/ {if ( index($4, \"llw0\") > 0 ){print $2} }'") at NacPlugin.cpp:697:19   frame #6: 0x000000010557c0a7 libnacplugin.dylib`NacPlugin::GetInterfaceAddrs(this=0x00007f795df04150, interfaces=size=0) at NacPlugin.cpp:503:35   frame #7: 0x000000010557a821 libnacplugin.dylib`NacPlugin::KeepAlive(this=0x00007f795df04150) at NacPlugin.cpp:156:5   frame #8: 0x000000010557a4d0 libnacplugin.dylib`NacPlugin::NacReport(this=0x00007f795df04150) at NacPlugin.cpp:84:9   frame #9: 0x000000010558eb38 libnacplugin.dylib`NacPlugin::PluginInit(this=0x00006000000b81e8)::$_0::operator()() const at NacPlugin.cpp:66:15   frame #10: 0x000000010558eae5 libnacplugin.dylib`decltype(__f=0x00006000000b81e8)::$_0>(fp)()) std::__1::__invoke<NacPlugin::PluginInit()::$_0>(NacPlugin::PluginInit()::$_0&&) at type_traits:3918:1   frame #11: 0x000000010558ea85 libnacplugin.dylib`void std::__1::__thread_execute<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, NacPlugin::PluginInit()::$_0>(__t=size=2, (null)=__tuple_indices<> @ 0x0000700005927f68)::$_0>&, std::__1::__tuple_indices<>) at thread:280:5   frame #12: 0x000000010558e305 libnacplugin.dylib`void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, NacPlugin::PluginInit()::$_0> >(__vp=0x00006000000b81e0) at thread:291:5   frame #13: 0x00007ff815fa2514 libsystem_pthread.dylib`_pthread_start + 125   frame #14: 0x00007ff815f9e02f libsystem_pthread.dylib`thread_start + 15 (lldb) di -f Foundation`-[NSConcreteTask processIdentifier]:    0x7ff816f82fe2 <+0>: pushq %rbp    0x7ff816f82fe3 <+1>: movq  %rsp, %rbp    0x7ff816f82fe6 <+4>: pushq %r14    0x7ff816f82fe8 <+6>: pushq %rbx    0x7ff816f82fe9 <+7>: movq  %rdi, %r14    0x7ff816f82fec <+10>: movq  0x408ad6f5(%rip), %rbx  ; NSConcreteTask._lock    0x7ff816f82ff3 <+17>: addq  %rdi, %rbx    0x7ff816f82ff6 <+20>: movq  %rbx, %rdi    0x7ff816f82ff9 <+23>: callq 0x7ff8171534e8      ; symbol stub for: os_unfair_lock_lock ->  0x7ff816f82ffe <+28>: movq  0x408ad713(%rip), %rax  ; NSConcreteTask._pid    0x7ff816f83005 <+35>: movl  (%r14,%rax), %r14d    0x7ff816f83009 <+39>: movq  %rbx, %rdi    0x7ff816f8300c <+42>: callq 0x7ff8171534f4      ; symbol stub for: os_unfair_lock_unlock    0x7ff816f83011 <+47>: movl  %r14d, %eax    0x7ff816f83014 <+50>: popq  %rbx    0x7ff816f83015 <+51>: popq  %r14    0x7ff816f83017 <+53>: popq  %rbp    0x7ff816f83018 <+54>: retq      0x7ff816f83019 <+55>: nop       0x7ff816f8301a <+56>: nop       0x7ff816f8301b <+57>: nop       0x7ff816f8301c <+58>: nop       0x7ff816f8301d <+59>: nop       0x7ff816f8301e <+60>: nop       0x7ff816f8301f <+61>: nop       0x7ff816f83020 <+62>: nop  * thread #42, queue = 'com.apple.root.utility-qos.overcommit'  * frame #0: 0x00007ff815f6b262 libsystem_kernel.dylib`__wait4 + 10   frame #1: 0x00007ff817086097 Foundation`__45-[NSConcreteTask launchWithDictionary:error:]_block_invoke.239 + 110   frame #2: 0x00007ff815debcc9 libdispatch.dylib`_dispatch_client_callout + 8   frame #3: 0x00007ff815dee746 libdispatch.dylib`_dispatch_continuation_pop + 460   frame #4: 0x00007ff815dffa5a libdispatch.dylib`_dispatch_source_invoke + 2150   frame #5: 0x00007ff815dfc1b4 libdispatch.dylib`_dispatch_kevent_worker_thread + 1554   frame #6: 0x00007ff815f9f0d7 libsystem_pthread.dylib`_pthread_wqthread + 398   frame #7: 0x00007ff815f9e01b libsystem_pthread.dylib`start_wqthread + 15 (lldb) f 1 frame #1: 0x00007ff817086097 Foundation`__45-[NSConcreteTask launchWithDictionary:error:]_block_invoke.239 + 110 Foundation`__45-[NSConcreteTask launchWithDictionary:error:]_block_invoke.239: ->  0x7ff817086097 <+110>: movl  %eax, %ebx    0x7ff817086099 <+112>: testl %eax, %eax    0x7ff81708609b <+114>: jns  0x7ff8170860a7      ; <+126>    0x7ff81708609d <+116>: callq 0x7ff817152bb2      ; symbol stub for: __error (lldb) di -f Foundation`__45-[NSConcreteTask launchWithDictionary:error:]_block_invoke.239:    0x7ff817086029 <+0>:  pushq %rbp    0x7ff81708602a <+1>:  movq  %rsp, %rbp    0x7ff81708602d <+4>:  pushq %r15    0x7ff81708602f <+6>:  pushq %r14    0x7ff817086031 <+8>:  pushq %r13    0x7ff817086033 <+10>: pushq %r12    0x7ff817086035 <+12>: pushq %rbx    0x7ff817086036 <+13>: subq  $0x68, %rsp    0x7ff81708603a <+17>: movq  %rdi, %r15    0x7ff81708603d <+20>: movq  0x41ded264(%rip), %rax  ; (void *)0x00007ff8577b9260: __stack_chk_guard    0x7ff817086044 <+27>: movq  (%rax), %rax    0x7ff817086047 <+30>: movq  %rax, -0x30(%rbp)    0x7ff81708604b <+34>: movq  0x20(%rdi), %r14    0x7ff81708604f <+38>: addq  0x407aa692(%rip), %r14  ; NSConcreteTask._lock    0x7ff817086056 <+45>: movq  %r14, %rdi    0x7ff817086059 <+48>: callq 0x7ff8171534e8      ; symbol stub for: os_unfair_lock_lock    0x7ff81708605e <+53>: movq  0x28(%r15), %rax    0x7ff817086062 <+57>: movq  0x407aa6b7(%rip), %rcx  ; NSConcreteTask._dsrc    0x7ff817086069 <+64>: movq  $0x0, (%rax,%rcx)    0x7ff817086071 <+72>: movq  0x30(%r15), %rdi    0x7ff817086075 <+76>: callq 0x7ff817152f66      ; symbol stub for: dispatch_source_cancel    0x7ff81708607a <+81>: movq  0x407aa697(%rip), %r13  ; NSConcreteTask._pid    0x7ff817086081 <+88>: leaq  -0x34(%rbp), %r12    0x7ff817086085 <+92>: movq  0x28(%r15), %rax    0x7ff817086089 <+96>: movl  (%rax,%r13), %edi    0x7ff81708608d <+100>: movq  %r12, %rsi    0x7ff817086090 <+103>: xorl  %edx, %edx    0x7ff817086092 <+105>: callq 0x7ff817153a04      ; symbol stub for: waitpid ->  0x7ff817086097 <+110>: movl  %eax, %ebx    0x7ff817086099 <+112>: testl %eax, %eax    0x7ff81708609b <+114>: jns  0x7ff8170860a7      ; <+126>    0x7ff81708609d <+116>: callq 0x7ff817152bb2      ; symbol stub for: __error    0x7ff8170860a2 <+121>: cmpl  $0x4, (%rax)    0x7ff8170860a5 <+124>: je   0x7ff817086085      ; <+92>    0x7ff8170860a7 <+126>: movl  $0xffffffff, %eax     ; imm = 0xFFFFFFFF

hi, @eskimo @Jack_Martin @Robert_Developer What is the final result about this problem, I'm also troubled by this problem. and my macos is 10.15.7

I think this should be apple's bug on 10.15.7 I make 3 tests as below: Preconditions: prepare the SampleNetworkExtension.app, put it on the network shared disk, and make a new VM for macos 10.15.7 1.copy SampleNetworkExtension.app to /Applications. run /Applications/SampleNetworkExtension.app, the popup is ok 2.clean up: move /Applications/SampleNetworkExtension.app to Trash and empty Trash, reboot system. copy SampleNetworkExtension.app to /Applications/test.app/Contents/PlugIns. run /Applications/test.app/Contents/PlugIns/SampleNetworkExtension.app, the popup will be null 3.clean up: move /Applications/test.app/Contents/PlugIns/SampleNetworkExtension.app to Trash and empty Trash, reboot system. copy SampleNetworkExtension.app to /Applications/test.app/Contents/PlugIns, and copy it to /Applications also. run /Applications/Contents/PlugIns/SampleNetworkExtension.app, the popup is ok. I do the same test on macos 11 or macos 12, that's ok. Maybe apple fixed it on macos 11

This code is worked fine from macOS 11.0 to macOS 12.3, Could anybody tell me how to adapt to macOS 12.4 for my code.