throws CancelledError, when I try to use Session File from one device to another

[glockOwner]

I tryed to login and do some actions with telethon on my device. Telethon created session file, code worked fine. Then I moved this code and session file into my hosting provider's server. The CancelledError throws on this server.

There is my code:
from telethon import TelegramClient

Use your own values from my.telegram.org

api_id = *********
api_hash = '********************************'

The first parameter is the .session file name (absolute paths allowed)

client = TelegramClient('SessionTest', api_id, api_hash)

async def main():
await client.send_message('***********', 'SESSIONTEST')

with client:
client.loop.run_until_complete(main())

And error traceback:

Unexpected exception in the receive loop
Traceback (most recent call last):
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/connection.py", line 332, in _recv_loop
data = await self._recv()
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/connection.py", line 369, in _recv
return await self._codec.read_packet(self._reader)
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/tcpfull.py", line 25, in read_packet
packet_len_seq = await reader.readexactly(8) # 4 and 4
File "/usr/lib/python3.6/asyncio/streams.py", line 674, in readexactly
yield from self._wait_for_data('readexactly')
File "/usr/lib/python3.6/asyncio/streams.py", line 464, in _wait_for_data
yield from self._waiter
concurrent.futures._base.CancelledError
Unhandled error while receiving data
Traceback (most recent call last):
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/mtprotosender.py", line 505, in _recv_loop
body = await self._connection.recv()
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/connection.py", line 301, in recv
raise err
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/connection.py", line 332, in _recv_loop
data = await self._recv()
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/connection.py", line 369, in _recv
return await self._codec.read_packet(self._reader)
File "/home/i/ivashk1f/.local/lib/python3.6/site-packages/telethon/network/connection/tcpfull.py", line 25, in read_packet
packet_len_seq = await reader.readexactly(8) # 4 and 4
File "/usr/lib/python3.6/asyncio/streams.py", line 674, in readexactly
yield from self._wait_for_data('readexactly')
File "/usr/lib/python3.6/asyncio/streams.py", line 464, in _wait_for_data
yield from self._waiter
concurrent.futures._base.CancelledError

[Lonami]

While "Unhandled error while receiving data" was a bug (solved by the above commit), the behavior should've been essentially the same.

If a disconnection occur it will exit.

I don't know why your provider disconnects the library but it's unlikely to be a problem with the library's code. Maybe the above fix will uncover the real cause.