Resync of partial state room failed

I joined a room via `matrix.org`. The faster join worked, but `matrix.org` then failed to respond to the `/federation/v1/state` request.

My server then tried some other servers that were in the room, but they all responded with 403s (presumably because `matrix.org` hadn't yet sent them the memo about my having joined).

Then my server gave up, and I have a basically unusable room (only 3 members visible, infinnispinnering on scrollback, can't send messages).

```
2025-11-21 10:16:37,615 - synapse.handlers.federation - 1926 - INFO - sync_partial_state_room-29 - Syncing state for room !ZrNQVaKcHWcGsgZfbN:matrix.org via matrix.org
2025-11-21 10:16:37,627 - synapse.handlers.federation_event - 626 - INFO - sync_partial_state_room-29 - Updating state for $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo
2025-11-21 10:16:37,655 - synapse.handlers.federation_event - 1130 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Event $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo is missing prev_events ['$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4']: calculating state for a backwards extremity
2025-11-21 10:16:37,655 - synapse.handlers.federation_event - 1152 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Requesting state after missing prev_event $HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4
2025-11-21 10:16:41,109 - synapse.http.matrixfederationclient - 369 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805031} [matrix.org] Completed request: 200 OK in 3.45 secs, got 1959 bytes - GET matrix-federation://matrix.org/_matrix/federation/v1/state_ids/%21ZrNQVaKcHWcGsgZfbN%3Amatrix.org?event_id=%24HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4
2025-11-21 10:16:41,163 - synapse.http.matrixfederationclient - 783 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805032} [matrix.org] Got response headers: 429 Too Many Requests
2025-11-21 10:16:41,164 - synapse.http.matrixfederationclient - 826 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805032} [matrix.org] Request failed: GET matrix-federation://matrix.org/_matrix/federation/v1/state/%21ZrNQVaKcHWcGsgZfbN%3Amatrix.org?event_id=%24HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4: HttpResponseException('429: Too Many Requests')
2025-11-21 10:16:41,164 - synapse.util.retryutils - 296 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - Connection to matrix.org was unsuccessful ((Failed to send request: HttpResponseException: 429: Too Many Requests)); backoff now 600000
2025-11-21 10:16:41,164 - synapse.handlers.federation_event - 1189 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Error attempting to resolve state at missing prev_events: Failed to send request: HttpResponseException: 429: Too Many Requests
2025-11-21 10:16:41,164 - synapse.handlers.federation - 2013 - INFO - sync_partial_state_room-29 - Failed to get state for !ZrNQVaKcHWcGsgZfbN:matrix.org at from matrix.org because ERROR 403: We can't get valid state history.
2025-11-21 10:16:41,164 - synapse.handlers.federation - 2021 - INFO - sync_partial_state_room-29 - Syncing state for room !ZrNQVaKcHWcGsgZfbN:matrix.org via lant.uk instead
2025-11-21 10:16:41,164 - synapse.handlers.federation_event - 626 - INFO - sync_partial_state_room-29 - Updating state for $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo
2025-11-21 10:16:41,190 - synapse.handlers.federation_event - 1130 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Event $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo is missing prev_events ['$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4']: calculating state for a backwards extremity
2025-11-21 10:16:41,194 - synapse.handlers.federation_event - 1152 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Requesting state after missing prev_event $HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4
2025-11-21 10:16:41,195 - synapse.http.federation.well_known_resolver - 278 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - Fetching https://lant.uk/.well-known/matrix/server
2025-11-21 10:16:41,552 - synapse.http.federation.well_known_resolver - 215 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - Response from .well-known: {'m.server': 'matrix.lant.uk:8448'}
2025-11-21 10:16:41,680 - synapse.http.matrixfederationclient - 783 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805033} [lant.uk] Got response headers: 403 Forbidden
2025-11-21 10:16:41,740 - synapse.http.matrixfederationclient - 873 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805033} [lant.uk] Request failed: GET matrix-federation://lant.uk/_matrix/federation/v1/state_ids/%21ZrNQVaKcHWcGsgZfbN%3Amatrix.org?event_id=%24HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4: HttpResponseException('403: Forbidden')
2025-11-21 10:16:41,741 - synapse.handlers.federation_event - 1189 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Error attempting to resolve state at missing prev_events: 403: Forbidden
2025-11-21 10:16:41,741 - synapse.handlers.federation - 2013 - INFO - sync_partial_state_room-29 - Failed to get state for !ZrNQVaKcHWcGsgZfbN:matrix.org at from lant.uk because ERROR 403: We can't get valid state history.
2025-11-21 10:16:41,741 - synapse.handlers.federation - 2021 - INFO - sync_partial_state_room-29 - Syncing state for room !ZrNQVaKcHWcGsgZfbN:matrix.org via banzan.uk instead
2025-11-21 10:16:41,741 - synapse.handlers.federation_event - 626 - INFO - sync_partial_state_room-29 - Updating state for $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo
2025-11-21 10:16:41,749 - synapse.handlers.federation_event - 1130 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Event $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo is missing prev_events ['$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4']: calculating state for a backwards extremity
2025-11-21 10:16:41,749 - synapse.handlers.federation_event - 1152 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Requesting state after missing prev_event $HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4
2025-11-21 10:16:41,753 - synapse.http.federation.well_known_resolver - 278 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - Fetching https://banzan.uk/.well-known/matrix/server
2025-11-21 10:16:41,839 - synapse.http.federation.well_known_resolver - 215 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - Response from .well-known: {'m.server': 'matrix.banzan.uk:8448'}
2025-11-21 10:16:41,945 - synapse.http.matrixfederationclient - 783 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805034} [banzan.uk] Got response headers: 403 Forbidden
2025-11-21 10:16:41,946 - synapse.http.matrixfederationclient - 873 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805034} [banzan.uk] Request failed: GET matrix-federation://banzan.uk/_matrix/federation/v1/state_ids/%21ZrNQVaKcHWcGsgZfbN%3Amatrix.org?event_id=%24HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4: HttpResponseException('403: Forbidden')
2025-11-21 10:16:41,948 - synapse.handlers.federation_event - 1189 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Error attempting to resolve state at missing prev_events: 403: Forbidden
2025-11-21 10:16:41,948 - synapse.handlers.federation - 2013 - INFO - sync_partial_state_room-29 - Failed to get state for !ZrNQVaKcHWcGsgZfbN:matrix.org at from banzan.uk because ERROR 403: We can't get valid state history.
2025-11-21 10:16:41,948 - synapse.handlers.federation - 2021 - INFO - sync_partial_state_room-29 - Syncing state for room !ZrNQVaKcHWcGsgZfbN:matrix.org via element.io instead
2025-11-21 10:16:41,948 - synapse.handlers.federation_event - 626 - INFO - sync_partial_state_room-29 - Updating state for $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo
2025-11-21 10:16:41,958 - synapse.handlers.federation_event - 1130 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Event $qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo is missing prev_events ['$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4']: calculating state for a backwards extremity
2025-11-21 10:16:41,959 - synapse.handlers.federation_event - 1152 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Requesting state after missing prev_event $HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4
2025-11-21 10:16:42,218 - synapse.http.matrixfederationclient - 783 - INFO - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805035} [element.io] Got response headers: 403 Forbidden
2025-11-21 10:16:42,218 - synapse.http.matrixfederationclient - 873 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo-$HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4 - {GET-O-805035} [element.io] Request failed: GET matrix-federation://element.io/_matrix/federation/v1/state_ids/%21ZrNQVaKcHWcGsgZfbN%3Amatrix.org?event_id=%24HL_q_4DO7XwvZNID-SVx_RAuJR4eKvIZX_sh5JeeiQ4: HttpResponseException('403: Forbidden')
2025-11-21 10:16:42,219 - synapse.handlers.federation_event - 1189 - WARNING - sync_partial_state_room-29-$qirgmWAkyjRxcwtGiz2UMDUYH1NzHlev2ULwLoaMzyo - Error attempting to resolve state at missing prev_events: 403: Forbidden
2025-11-21 10:16:42,220 - synapse.handlers.federation - 2000 - ERROR - sync_partial_state_room-29 - Failed to get state for !ZrNQVaKcHWcGsgZfbN:matrix.org at from element.io because ERROR 403: We can't get valid state history., giving up!
2025-11-21 10:16:42,220 - synapse.metrics.background_process_metrics - 273 - ERROR - sync_partial_state_room-29 - Background process 'sync_partial_state_room' threw an exception
apture point (most recent call last):
File "", line 1, in
File "/home/synapse/src/synapse/synapse/app/homeserver.py", line 417, in main
run(hs)
File "/home/synapse/src/synapse/synapse/app/homeserver.py", line 396, in run
_base.start_reactor(
File "/home/synapse/src/synapse/synapse/app/_base.py", line 204, in start_reactor
run()
File "/home/synapse/src/synapse/synapse/app/_base.py", line 186, in run
run_command()
File "/home/synapse/src/synapse/synapse/app/_base.py", line 161, in
run_command: Callable[[], None] = lambda: reactor.run(),
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/base.py", line 697, in run
self.mainLoop()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/base.py", line 708, in mainLoop
self.doIteration(t)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/epollreactor.py", line 244, in doPoll
log.callWithLogger(selectable, _drdw, selectable, fd, event)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/python/log.py", line 96, in callWithLogger
return callWithContext({"system": lp}, func, *args, **kw)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/python/log.py", line 80, in callWithContext
return context.call({ILogContext: newCtx}, func, *args, **kw)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/python/context.py", line 117, in callWithContext
return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/python/context.py", line 82, in callWithContext
return func(*args, **kw)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/posixbase.py", line 491, in _doReadOrWrite
why = selectable.doRead()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/tcp.py", line 250, in doRead
return self._dataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/tcp.py", line 255, in _dataReceived
rval = self.protocol.dataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/endpoints.py", line 156, in dataReceived
return self._wrappedProtocol.dataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/protocols/tls.py", line 339, in dataReceived
self._flushReceiveBIO()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/protocols/tls.py", line 305, in _flushReceiveBIO
ProtocolWrapper.dataReceived(self, bytes)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/protocols/policies.py", line 110, in dataReceived
self.wrappedProtocol.dataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1682, in dataReceived
self._parser.dataReceived(bytes)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 379, in dataReceived
HTTPParser.dataReceived(self, data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/protocols/basic.py", line 555, in dataReceived
why = self.rawDataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 288, in rawDataReceived
self.bodyDecoder.dataReceived(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/http.py", line 2164, in dataReceived
goOn = getattr(self, "_dataReceived_" + self.state)()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/http.py", line 2123, in _dataReceived_TRAILER
self.finishCallback(data)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 445, in _finished
self.finisher(rest)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1057, in dispatcher
return func(*args, **kwargs)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1640, in _finishResponse_WAITING
self._disconnectParser(reason)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1664, in _disconnectParser
parser.connectionLost(reason)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 550, in connectionLost
self.response._bodyDataFinished()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1057, in dispatcher
return func(*args, **kwargs)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/web/_newclient.py", line 1301, in _bodyDataFinished_CONNECTED
self._bodyProtocol.connectionLost(reason)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/treq/content.py", line 77, in connectionLost
self.finished.callback(None)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 891, in callback
self._startRunCallbacks(result)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 998, in _startRunCallbacks
self._runCallbacks()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 1092, in _runCallbacks
current.result = callback( # type: ignore[misc]
File "/home/synapse/src/synapse/synapse/util/async_helpers.py", line 827, in success_cb
new_d.callback(val)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 891, in callback
self._startRunCallbacks(result)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 998, in _startRunCallbacks
self._runCallbacks()
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 1092, in _runCallbacks
current.result = callback( # type: ignore[misc]
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 1803, in _gotResultInlineCallbacks
_inlineCallbacks(r, gen, status, context)
File "/home/synapse/poetry-env/matrix-synapse-o-qzlfnx-py3.11/lib/python3.11/site-packages/twisted/internet/defer.py", line 1857, in _inlineCallbacks
result = context.run(gen.send, result)
Traceback (most recent call last):
File "/home/synapse/src/synapse/synapse/handlers/federation_event.py", line 1159, in _compute_event_context_with_maybe_missing_prevs
await self._get_state_ids_after_missing_prev_event(
File "/home/synapse/src/synapse/synapse/logging/opentracing.py", line 929, in _wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/logging/opentracing.py", line 929, in _wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/handlers/federation_event.py", line 1235, in _get_state_ids_after_missing_prev_event
) = await self._federation_client.get_room_state_ids(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/logging/opentracing.py", line 929, in _wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/logging/opentracing.py", line 929, in _wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/federation/federation_client.py", line 636, in get_room_state_ids
result = await self.transport_layer.get_room_state_ids(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/federation/transport/client.py", line 90, in get_room_state_ids
return await self.client.get_json(
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/http/matrixfederationclient.py", line 1239, in get_json
json_dict, _ = await self.get_json_with_headers(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/http/matrixfederationclient.py", line 1339, in get_json_with_headers
response = await self._send_request_with_optional_trailing_slash(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/http/matrixfederationclient.py", line 517, in _send_request_with_optional_trailing_slash
response = await self._send_request(request, **send_request_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/http/matrixfederationclient.py", line 822, in _send_request
raise exc
synapse.api.errors.HttpResponseException: 403: Forbidden

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/synapse/src/synapse/synapse/metrics/background_process_metrics.py", line 271, in run
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/handlers/federation.py", line 1849, in _sync_partial_state_room_wrapper
await self._sync_partial_state_room(
File "/home/synapse/src/synapse/synapse/handlers/federation.py", line 1977, in _sync_partial_state_room
await self._federation_event_handler.update_state_for_partial_state_event(
File "/home/synapse/src/synapse/synapse/handlers/federation_event.py", line 634, in update_state_for_partial_state_event
context = await self._compute_event_context_with_maybe_missing_prevs(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/logging/opentracing.py", line 929, in _wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/synapse/src/synapse/synapse/handlers/federation_event.py", line 1192, in _compute_event_context_with_maybe_missing_prevs
raise FederationError(
synapse.api.errors.FederationError: ERROR 403: We can't get valid state history.

```