ValueError: invalid message type: 18 between Server 5.0.1 and Client 6.0.0

[d1rksm33ts]

Describe the issue briefly here, including:

Environment

Server running on python3.6 using rpyc 5.0.1
Client running on python3.11 using rpyc 6.0.0

Client gets an invalid message type: 18

File "/usr/lib/python3.11/site-packages/rpyc/core/protocol.py", line 432, in _dispatch
raise ValueError(f"invalid message type: {msg!r}")
ValueError: invalid message type: 18

rpyc.version
'6.0.0'

When I install rpyc 5.3.1 on the client side, it works fine.

Is it to be expected that 5.x <-> 6.x is throwing this Error?

[meesokim]

I've got the same problem. Currently I reverted to 5.3.1 instead of 6.0.0 to avoid the error.

[inaky-intc]

Same issue here, 6.x client needed because of Python 3.12 and 5.x server in production area.