Admin page with panel.serve error log

[hyamanieu]

ALL software version info

Panel Server running on following versions:
Python 3.9.12 (main, Apr 4 2022, 05:22:27) [MSC v.1916 64 bit (AMD64)]
Panel: 0.14.0
Bokeh: 2.4.2
Param: 1.12.1

Description of expected behavior and the observed behavior

Version 0.14.0 claims than passing admin=True into the pn.serve function should work exactly like the command line panel serve --admin.

However after starting python main.py and accessing any dashboard served

1. I have "0 active session" shown in the Admin Overview tab when accessing any dashboard (although I can see the session in the Admin Logs tab, see further)
2. I get the following error upon accessing for the first time the "admin" page: WARNING:bokeh.core.validation.check:W-1002 (EMPTY_LAYOUT): Layout has no children: Row(id='17416', ...)
3. I get an error in the terminal upon accessing for the first time the dashboard (see below)
4. I get an error in the terminal upon clicking on one of the row within the Admin Logs (see also below)

Complete, minimal, self-contained example code that reproduces the issue

Here below is saved under a main.py

Due to #3970 , I had to add a self-made index.html which is not in this MVE.
You can copy the 0.13.1 index.html in the same folder as main.py and rename it index_mvp_panel014.html

import param
import panel as pn

import numpy as np
import holoviews as hv

pn.extension(sizing_mode="stretch_width")


class Meta_Dashboard(param.Parameterized):
    site = "MVP Panel 0.14 with admin"
    title = "abstract"


    def make_panel(self):
        """
        Abstract function. Must be defined in children classes
        """
        pass
    
    @classmethod
    def instantiate_new_dashboard(cls):
        dashboard_instance = cls()
        return dashboard_instance.make_panel()


class Random_Number_Generator(Meta_Dashboard):

    title="Random_Number_Generator"

    def make_panel(self):
        def generate_random_number(event=None):
            static_text.value = np.random.randint(low=100000, high=200000)

        def toggle_periodic_callback(event):
            if event.new is True:
                periodic_cb.start()
                periodic_toggle.name="STOP Periodic Generation"
            else:
                periodic_cb.stop()
                periodic_toggle.name="START Periodic Generation"
                
        def update_period(event):
            periodic_cb.period = event.new

        static_text = pn.widgets.StaticText(name='Periodic Random Number Generator',
                                            value='000000')

        generate_button = pn.widgets.Button(name='GENERATE New Number')
        generate_button.on_click(generate_random_number)

        periodic_toggle = pn.widgets.Toggle(name='START Periodic Generation',
                                            value=False, button_type='primary')
        periodic_toggle.param.watch(toggle_periodic_callback, 'value')

        period = pn.widgets.Spinner(name="Period (ms)", value=500, step=50, start=50)
        period.param.watch(update_period, 'value')

        periodic_cb = pn.state.add_periodic_callback(
            generate_random_number, period=period.value, start=False)

        col = pn.Column(generate_button, period, periodic_toggle, static_text)
        dashboard = pn.template.FastListTemplate(
            site=self.site, 
            title=self.title, 
            base_url='localhost',
            main=[
                "This example creates a **random number generator** that updates periodically or with the click of a button.\n\nThis demonstrates how to add a **periodic callback** and how to link a button and a toggle to a couple of callbacks.",
                col,
            ], main_max_width="768px",
        )
        return dashboard
    

class Distribution_Tabs(Meta_Dashboard):
    title = "Distribution_Tabs"
    def make_panel(self):
        distributions = {
            'NORMAL': np.random.normal,
            'UNIFORM': np.random.uniform,
            'LOG-NORMAL': np.random.lognormal,
            'EXPONENTIAL': np.random.exponential
        }

        checkboxes = pn.widgets.ToggleGroup(options=distributions, behavior='radio', button_type="success")
        slider = pn.widgets.IntSlider(name='Number of observations', value=500, start=0, end=2000)

        @pn.depends(checkboxes.param.value, slider.param.value)
        def tabs(distribution, n):
            values = hv.Dataset(distribution(size=n), 'values')
            return pn.Tabs(
                ('Plot', values.hist(adjoin=False).opts(
                    responsive=True, max_height=500, padding=0.1, color="#00aa41")),
                ('Summary', values.dframe().describe().T),
                ('Table', hv.Table(values)),
            )

        selections = pn.Column('### Distribution Type', checkboxes, slider)

        return pn.template.BootstrapTemplate(site=self.site, 
        title=self.title, 
        base_url='localhost',
        main=["This example demonstrates **how to plot several different types of outputs in a Tab**.", 
        selections, 
        tabs])


if __name__ == '__main__':
    from pathlib import Path
    index_html = str(Path('.').absolute()/'index_mvp_panel014.html')
    pn.serve({
        Random_Number_Generator.title: Random_Number_Generator.instantiate_new_dashboard,
        Distribution_Tabs.title: Distribution_Tabs.instantiate_new_dashboard,
    },    
    show=False,
    port=8082,
    autoreload=True,
    websocket_origin=['localhost:8082', 
                    ],
    admin=True,
    index=index_html,
    )

Stack traceback and/or browser JavaScript console output

Logs from the terminal upon starting a dashboard

ERROR:tornado.application:Exception in callback functools.partial(<bound method IOLoop._discard_future_result of <tornado.platform.asyncio.AsyncIOMainLoop object at 0x00000274CB87CD60>>, <Task finished name='Task-2657' coro=<_needs_document_lock.<locals>._needs_document_lock_wrapper() done, defined at C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py:77> exception=ValueError("'Session 2700658953424 launching' is not in list")>)
Traceback (most recent call last):
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\tornado\ioloop.py", line 741, in _run_callback
    ret = callback()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\tornado\ioloop.py", line 765, in _discard_future_result       
    future.result()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 93, in _needs_document_lock_wrapper
    result = func(self, *args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 227, in with_document_locked   
    return func(*args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 450, in wrapper
    return invoke_with_curdoc(doc, invoke)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 408, in invoke_with_curdoc 
    return f()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 449, in invoke
    return f(*args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 179, in remove_then_invoke 
    return callback()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\io\admin.py", line 219, in update_cds
    index = cds.data['msg'].index(LOG_SESSION_LAUNCHING % sid)
ValueError: 'Session 2700658953424 launching' is not in list
ERROR:tornado.application:Exception in callback functools.partial(<bound method IOLoop._discard_future_result of <tornado.platform.asyncio.AsyncIOMainLoop object at 0x00000274CB87CD60>>, <Task finished name='Task-2656' coro=<_needs_document_lock.<locals>._needs_document_lock_wrapper() done, defined at C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py:77> exception=ValueError("'Session 2700658953424 launching' is not in list")>)
Traceback (most recent call last):
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\tornado\ioloop.py", line 741, in _run_callback
    ret = callback()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\tornado\ioloop.py", line 765, in _discard_future_result       
    future.result()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 93, in _needs_document_lock_wrapper
    result = func(self, *args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 227, in with_document_locked   
    return func(*args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 450, in wrapper
    return invoke_with_curdoc(doc, invoke)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 408, in invoke_with_curdoc 
    return f()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 449, in invoke
    return f(*args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 179, in remove_then_invoke 
    return callback()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\io\admin.py", line 219, in update_cds
    index = cds.data['msg'].index(LOG_SESSION_LAUNCHING % sid)
ValueError: 'Session 2700658953424 launching' is not in list

Admin Logs copied from the generated CSV:

datetime	level	app	session	message
10.10.2022 14:52	DEBUG	panel.viewable.Location	2,70066E+12	finished processing events {'pathname': '/Distribution_Tabs', 'href': 'http://localhost:8082/Distribution_Tabs', 'hostname': 'localhost', 'protocol': 'http:', 'port': '8082'}
10.10.2022 14:52	DEBUG	panel.viewable.Location	2,70066E+12	received events {'pathname': '/Distribution_Tabs', 'href': 'http://localhost:8082/Distribution_Tabs', 'hostname': 'localhost', 'protocol': 'http:', 'port': '8082'}
10.10.2022 14:52	INFO	panel.io.server	2,70066E+12	created

Error in the terminal upon clicking on one of the rows within the Admin Logs tab (in this example the second row, Key 1):

ERROR:bokeh.server.protocol_handler:error handling message
 message: Message 'PATCH-DOC' content: {'events': [{'kind': 'MessageSent', 'msg_type': 'bokeh_event', 'msg_data': {'event_name': 'cell-click', 'event_values': {'column': 'message', 'row': 1}}}], 'references': []}
 error: KeyError(1)
Traceback (most recent call last):
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\protocol_handler.py", line 97, in handle
    work = await handler(message, connection)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 93, in _needs_document_lock_wrapper
    result = func(self, *args, **kwargs)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\server\session.py", line 287, in _handle_patch
    message.apply_to_document(self.document, self)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\protocol\messages\patch_doc.py", line 115, in apply_to_document
    invoke_with_curdoc(doc, lambda: doc.apply_json_patch(self.content, setter))
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 408, in invoke_with_curdoc 
    return f()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\protocol\messages\patch_doc.py", line 115, in <lambda>  
    invoke_with_curdoc(doc, lambda: doc.apply_json_patch(self.content, setter))
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\document.py", line 391, in apply_json_patch    
    DocumentPatchedEvent.handle_json(self, event_json, references, setter)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\events.py", line 259, in handle_json
    handler(doc, event_json, references, setter)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\events.py", line 300, in _handle_json
    cb(event_json["msg_data"])
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 355, in trigger_json_event 
    model._trigger_event(event)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\util\callback_manager.py", line 119, in _trigger_event  
    self.document.callbacks.notify_event(cast(Model, self), event, invoke)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 247, in notify_event       
    invoke_with_curdoc(doc, callback_invoker)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\document\callbacks.py", line 408, in invoke_with_curdoc 
    return f()
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\bokeh\util\callback_manager.py", line 115, in invoke
    cast(EventCallbackWithEvent, callback)(event)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\reactive.py", line 428, in _server_event
    self._comm_event(doc, event)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\reactive.py", line 415, in _comm_event
    state._handle_exception(e)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\io\state.py", line 391, in _handle_exception
    raise exception
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\reactive.py", line 413, in _comm_event
    self._process_bokeh_event(doc, event)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\reactive.py", line 350, in _process_bokeh_event
    self._process_event(event)
  File "C:\Users\hy.amanieu\Anaconda3\envs\youpi\lib\site-packages\panel\widgets\tables.py", line 1158, in _process_event        
    idx = self._index_mapping[event.row]
KeyError: 1

Screenshots or screencasts of the bug in action