Question: What does 'Old version' error message mean on MT4/MT5 platforms?
The “Old version” error indicates that you have an old version of the platform installed on your PC that is no longer compatible with the servers.
You’ll need to update your platform by downloading the latest version of the platform.
Actually, the MetaTrader trading platform is updated to new version often like every few weeks.(sometimes a few days…) And the trading platform is set to update itself automatically by default.
You can also change the setting to not update it automatically though, normally you wouldn’t have this problem(old version) by each update unless there is some updates related to the compatibility of the trading server.
Some traders even stop the update for a while when they don’t like the new version of the trading platform.
Anyway, if you like to update the MetaTrader trading platform to the new version, then you can re-install it from your broker’s official website, or right click on the MetaTrader icon and select “run as administrator” and that will update the software to the newest version.