If you have been hyped for the release of Terraria’s new 1.4 updated, Journey’s End, it may have knocked the wind out of your sales when you got a bug. This bug can crop up when trying to connect to another game and will tell you that Terreria has lost connection.
The main cause of this bug appears to be a version mismatch between the people who are trying to play together via Steam, and we haven’t heard any reports yet of people being impact by the issue in singleplayer modes.
To fix the issue, you will need everyone in the party to verify the integrity of their install files. This can be done by right-clicking on the game in your Library, then clicking on Properties, and clicking on the Local Files tab. The verify option is the second last button on the list. It is impossible to know which player actually has the wrong files, so you will need both parties to do this.
While it might sound like something that shouldn’t happen, sometimes a mistake in an update means old files can interfere with your attempt to play the game. All it can take is a couple of files not being updated for the issues to occur. If verifying the caches shows no problems, you can just uninstall the game, reinstall it, and try to connect to your friend again.
This isn’t a huge issue with Terraria, as the install size of the game is so small. If there is a problem, the Steam client should automatically repair the installation for you. This should fix the problem for you, and you will be able to connect with your friends and begin exploring each other’s worlds.