Cannot join session from one editor to another

There are two launched editors of game (on two machines, version of code and assets is almost identical), but when I tried to use “open 10.0.0.238” command, I got no any success.

LogNet:Warning: Network Failure: PendingNetDriver[OutdatedClient]: The match you are trying to join is running an incompatible version of the game. Please try upgrading your game version.

How to simplify project testing with two machines? One is server (may be dedicated server) and another is client(s) in (preferably editor windows).

I love any information about this. Thank you for attention!