I noticed that on gitter you replied to Andrew comment from July 30th 2019 18:16, quoted here for context:
DocumentLifeCycleHandler on_session_destroyed callback <bound method Viewable._server_destroy of GridSpec(sizing_mode='stretch_both') failed with following error: 'tuple' object has no attribute '_cleanup'
through panel serve
And yes, that error means something but there’s already an issue.
Can you please point me to the issue? I’m having the same problem and I’m not sure if there’s anything I can do interim to get around it.