When setting display name more graciously handle failures to update room state.

synapse/handlers/profile.py

@@ -212,10 +212,16 @@ class ProfileHandler(BaseHandler):
             )
 
             msg_handler = self.hs.get_handlers().message_handler
-            yield msg_handler.create_and_send_event({
-                "type": EventTypes.Member,
-                "room_id": j.room_id,
-                "state_key": user.to_string(),
-                "content": content,
-                "sender": user.to_string()
-            }, ratelimit=False)
+            try:
+                yield msg_handler.create_and_send_event({
+                    "type": EventTypes.Member,
+                    "room_id": j.room_id,
+                    "state_key": user.to_string(),
+                    "content": content,
+                    "sender": user.to_string()
+                }, ratelimit=False)
+            except Exception as e:
+                logger.warn(
+                    "Failed to update join event for room %s - %s",
+                    j.room_id, str(e.message)
+                )