Leaving or posting into a specific room results into an error

[matrixbot]

This issue has been migrated from #16122.

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Description

When leaving or posting into one specific room Synapse returns an error.

Seems like an invalid state for this specific room / contact.

The room is on another server which does not run synapse but dendrite.

Steps to reproduce

• Not sure if this is reproducable.

Homeserver

Private one

Synapse Version

1.90.0

Installation Method

Docker (matrixdotorg/synapse)

Database

PostgreSQL single server 15.0-alpine docker

Workers

Single process

Platform

Linux with a Kubernetes cluster

Configuration

No response

Relevant log output

2023-08-16 14:00:29,996 - synapse.http.server - 134 - ERROR - POST-60649 - Failed handle request via 'RoomMembershipRestServlet': <XForwardedForRequest at 0x7f7eb9f93b10 method='POST' uri='/_matrix/client/r0/rooms/{room_id}/leave' clientproto= │
│ Traceback (most recent call last):                                                                                                                                                                                                                                        │
│   File "/usr/local/lib/python3.11/site-packages/synapse/http/server.py", line 320, in _async_render_wrapper                                                                                                                                                               │
│     callback_return = await self._async_render(request)                                                                                                                                                                                                                   │
│   File "/usr/local/lib/python3.11/site-packages/synapse/http/server.py", line 532, in _async_render                                                                                                                                                                       │
│     callback_return = await raw_callback_return                                                                                                                                                                                                                           │
│   File "/usr/local/lib/python3.11/site-packages/synapse/rest/client/room.py", line 1072, in on_POST                                                                                                                                                                       │
│     return await self._do(request, requester, room_id, membership_action, None)                                                                                                                                                                                           │
│   File "/usr/local/lib/python3.11/site-packages/synapse/rest/client/room.py", line 1045, in _do                                                                                                                                                                           │
│     await self.room_member_handler.update_membership(                                                                                                                                                                                                                     │
│   File "/usr/local/lib/python3.11/site-packages/synapse/handlers/room_member.py", line 627, in update_membership                                                                                                                                                          │
│     result = await self.update_membership_locked(                                                                                                                                                                                                                         │
│   File "/usr/local/lib/python3.11/site-packages/synapse/handlers/room_member.py", line 1088, in update_membership_locked                                                                                                                                                  │
│     return await self._local_membership_update(                                                                                                                                                                                                                           │
│   File "/usr/local/lib/python3.11/site-packages/synapse/handlers/room_member.py", line 482, in _local_membership_update                                                                                                                                                   │
│     await self.event_creation_handler.handle_new_client_event(                                                                                                                                                                                                            │
│   File "/usr/local/lib/python3.11/site-packages/synapse/util/metrics.py", line 113, in measured_func                                                                                                                                                                      │
│     r = await func(self, *args, **kwargs)                                                                                                                                                                                                                                 │
│   File "/usr/local/lib/python3.11/site-packages/synapse/handlers/message.py", line 1478, in handle_new_client_event                                                                                                                                                       │
│     result, _ = await make_deferred_yieldable(                                                                                                                                                                                                                            │
│   File "/usr/local/lib/python3.11/site-packages/twisted/internet/defer.py", line 1697, in _inlineCallbacks                                                                                                                                                                │
│     result = context.run(gen.send, result)                                                                                                                                                                                                                                │
│   File "/usr/local/lib/python3.11/site-packages/synapse/handlers/message.py", line 1514, in _persist_events                                                                                                                                                               │
│     await self._bulk_push_rule_evaluator.action_for_events_by_user(                                                                                                                                                                                                       │
│   File "/usr/local/lib/python3.11/site-packages/synapse/push/bulk_push_rule_evaluator.py", line 314, in action_for_events_by_user                                                                                                                                         │
│     await self._action_for_event_by_user(event, context, event_id_to_event)                                                                                                                                                                                               │
│   File "/usr/local/lib/python3.11/site-packages/synapse/util/metrics.py", line 113, in measured_func                                                                                                                                                                      │
│     r = await func(self, *args, **kwargs)                                                                                                                                                                                                                                 │
│   File "/usr/local/lib/python3.11/site-packages/synapse/push/bulk_push_rule_evaluator.py", line 379, in _action_for_event_by_user                                                                                                                                         │
│     keys = list(notification_levels.keys())                                                                                                                                                                                                                               │
│ AttributeError: 'NoneType' object has no attribute 'keys'

Anything else that would be useful to know?

No response