Stack trace:

  File "C:\projects\botkit\botkit\agnostic\pyrogram_chat_resolver.py", line 52, in resolve_chat_by_title_regex
    async for d in self.client.iter_dialogs(limit=LIMIT):
              │    │    │      │                  └ 150
              │    │    │      └ <function IterDialogs.iter_dialogs at 0x000001DD4E289AF0>
              │    │    └ <app.clients.telegram.userclients.UserClient object at 0x000001DD540443D0>
              │    └ <botkit.agnostic.pyrogram_chat_resolver.PyrogramChatResolver object at 0x000001DD52395E20>
              └ pyrogram.types.Dialog(chat=pyrogram.types.Chat(id=855155169, type='bot', is_verified=False, is_restricted=False, is_scam=Fals...

  File "C:\git\pyrogram\pyrogram\methods\chats\iter_dialogs.py", line 81, in iter_dialogs
    offset_date = dialogs[-1].top_message.date
                  └ pyrogram.types.List([pyrogram.types.Dialog(chat=pyrogram.types.Chat(id=-1001050905835, type='supergroup', is_verified=False, ...

AttributeError: 'NoneType' object has no attribute 'date'

It seems to be an off-by-one error, as 99 dialogs have the top_message here, but the 100th does not. Maybe that's also a coincidence, but in any case in a debug session I confirmed that top_message may be unset.