Hello Jozef,
it seems that this problem persists in the current docker image.
When I try to open the extensions window, ISAAC Sim crashes.
Here are the logs:
2021-06-16 12:02:02 [232,834ms] [Info] [carb.python] [omni.kit.registry.nucleus]: (syncing index (async)) copying: omniverse://kit-extensions.ov.nvidia.com/exts/kit/default/2/index.toml -> /tmp/tmp91glxx3d/index.toml
2021-06-16 12:02:02 [232,836ms] [Info] [omni.client.plugin] Tick: provider_nucleus: Received username/password from application for kit-extensions.ov.nvidia.com:3009
2021-06-16 12:02:02 [232,836ms] [Info] [omni.client.plugin] Tick: provider_nucleus: Connecting to kit-extensions.ov.nvidia.com:3009 as svc-kit-extension-downloader using new authentication method
2021-06-16 12:02:02 [232,837ms] [Info] [omni.client.plugin] Tick: authentication: Discovery(kit-extensions.ov.nvidia.com:3009): Searching for OmniAuth.idl.ts : Credentials at wss://kit-extensions.ov.nvidia.com/omni/discovery
2021-06-16 12:02:02 [232,838ms] [Info] [omni.client.plugin] Tick: authentication: Discovery(wss://kit-extensions.ov.nvidia.com/omni/discovery): Create transport failed: Unable to connect to kit-extensions.ov.nvidia.com:443
2021-06-16 12:02:02 [232,838ms] [Warning] [omni.client.plugin] Tick: authentication: Could not resolve host name "kit-extensions.ov.nvidia.com"
2021-06-16 12:02:02 [232,838ms] [Info] [omni.client.plugin] Tick: authentication: Discovery(kit-extensions.ov.nvidia.com:3009): Searching for OmniAuth.idl.ts : Credentials at ws://kit-extensions.ov.nvidia.com:3333
2021-06-16 12:02:02 [232,839ms] [Info] [omni.client.plugin] Tick: authentication: Discovery(ws://kit-extensions.ov.nvidia.com:3333): Create transport failed: Unable to connect to kit-extensions.ov.nvidia.com:3333
2021-06-16 12:02:02 [232,839ms] [Warning] [omni.client.plugin] Tick: authentication: Could not resolve host name "kit-extensions.ov.nvidia.com"
2021-06-16 12:02:02 [232,839ms] [Info] [omni.client.plugin] Tick: provider_nucleus: Connecting to kit-extensions.ov.nvidia.com:3009 as svc-kit-extension-downloader using old authentication method
2021-06-16 12:02:02 [232,841ms] [Info] [omni.client.plugin] Tick: provider_nucleus: Connecting to kit-extensions.ov.nvidia.com:3009 failed: Connection refused
2021-06-16 12:02:02 [233,303ms] [Info] [carb.python] [omni.kit.registry.nucleus]: result: Result.ERROR_CONNECTION
2021-06-16 12:02:02 [233,303ms] [Error] [carb.python] [omni.kit.registry.nucleus]: syncing index failed. Result: Result.ERROR_CONNECTION
2021-06-16 12:02:03 [233,455ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.events.plugin.so!carbOnPluginStartup
2021-06-16 12:02:02 [233,303ms] [Info] [carb.python] [omni.kit.registry.nucleus]: [kit/default] refresh_index() -> failure.
2021-06-16 12:02:03 [233,462ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.tasking.plugin.so!std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (carb::tasking::Scheduler::*)(unsigned int, int, carb::cpp20::latch*), carb::tasking::Scheduler*, unsigned int, int, carb::cpp20::latch*> > >::_M_run()
2021-06-16 12:02:03 [233,469ms] [Fatal] [carb.crashreporter-breakpad.plugin] libomni.usd.so!std::_Function_base::_Base_manager<omni::usd::OmniUsdMessenger::Impl::Impl(omni::usd::UsdContext*)::{lambda(carb::events::IEvent*)#1}>::_M_manager(std::_Any_data&, std::_Function_base::_Base_manager<omni::usd::OmniUsdMessenger::Impl::Impl(omni::usd::UsdContext*)::{lambda(carb::events::IEvent*)#1}> const&, std::_Manager_operation)
2021-06-16 12:02:03 [233,477ms] [Fatal] [carb.crashreporter-breakpad.plugin] libpthread.so.0!funlockfile
2021-06-16 12:02:03 [233,483ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.imaging.plugin.so!_init
2021-06-16 12:02:03 [233,489ms] [Fatal] [carb.crashreporter-breakpad.plugin] libgpu.foundation.so!void std::this_thread::sleep_for<long, std::ratio<1l, 1000000l> >(std::chrono::duration<long, std::ratio<1l, 1000000l> > const&)
2021-06-16 12:02:03 [233,496ms] [Fatal] [carb.crashreporter-breakpad.plugin] libgpu.foundation.so!void std::this_thread::sleep_for<long, std::ratio<1l, 1000000l> >(std::chrono::duration<long, std::ratio<1l, 1000000l> > const&)
2021-06-16 12:02:03 [233,503ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.assets.plugin.so!carbOnPluginShutdown
2021-06-16 12:02:03 [233,510ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.assets.plugin.so!carbOnPluginShutdown
2021-06-16 12:02:03 [233,516ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.assets.plugin.so!std::__shared_count<(__gnu_cxx::_Lock_policy)2>::operator=(std::__shared_count<(__gnu_cxx::_Lock_policy)2> const&)
2021-06-16 12:02:03 [233,523ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.tasking.plugin.so!std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (carb::tasking::ThreadPool::*)(), carb::tasking::ThreadPool*> > >::~_State_impl()
2021-06-16 12:02:03 [233,530ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.tasking.plugin.so!std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (carb::tasking::ThreadPool::*)(), carb::tasking::ThreadPool*> > >::~_State_impl()
2021-06-16 12:02:03 [233,536ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.tasking.plugin.so!std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (carb::tasking::ThreadPool::*)(), carb::tasking::ThreadPool*> > >::~_State_impl()
2021-06-16 12:02:03 [233,543ms] [Fatal] [carb.crashreporter-breakpad.plugin] libcarb.tasking.plugin.so!make_fcontext
Segmentation fault (core dumped)