AutoTrading is disabled in MT5

Causes, most likely first

1. The global Algo Trading button is off (retcode 10027)

Look at the toolbar at the top of MetaTrader. The Algo Trading button must be green, not red. Click it once, or press Ctrl+E. This single toggle overrides every other setting — an EA can be loaded, initialised and generating signals while this is off, and it will place no orders at all. It is the answer far more often than anything else on this page. The Journal reports it as retcode 10027, TRADE_RETCODE_CLIENT_DISABLES_AT: the refusal came from your own terminal. Note that Ctrl+E is also how people switch it off by accident — it is next to Ctrl+W and Ctrl+R on the keyboard, and a mistyped shortcut disables every EA at once with no confirmation.

2. The EA itself is not permitted to trade

Right-click the chart, choose Expert Advisors then Properties, open the Common tab and tick "Allow Algo Trading". This is a per-EA permission that is separate from the global button, and both must be enabled. Reattaching an EA sometimes resets it to the platform default.

3. MetaTrader is switching it off for you, by design

Tools, then Options, then the Expert Advisors tab. Two checkboxes there — "Disable algorithmic trading when switching accounts" and "...when changing the profile" — turn the master button off automatically whenever you do either. They are enabled by default on many builds. If your EA stops every time you log into a different account, this is why, and it will keep happening until the boxes are cleared.

4. A platform update reset the setting

Some MetaTrader builds turn algorithmic trading off after updating, as a safety default. If a previously working setup stopped overnight and nothing else changed, this is almost certainly why. Re-enable it and check the Journal tab for the update entry to confirm.

5. You are logged in with the investor password, not the trading password

Broker account emails list two passwords. The investor password opens the account read-only: charts, history and the Journal all work normally, and every order, manual or automated, is refused. Because the login looks completely ordinary this is routinely mistaken for a server-side block, and it is the first thing most broker support desks check. Log out and back in with the master (trader) password. Nothing else needs to change, and the EA was never at fault.

6. The broker has disabled automated trading on the account (retcode 10026)

Rare, but it happens on some demo contests, on accounts flagged for review, and on certain account types that simply do not permit EAs. The Journal shows retcode 10026, TRADE_RETCODE_SERVER_DISABLES_AT, and the wording is "Autotrading disabled by server" rather than "by client". Nothing on your machine will fix this one: no button, no setting, no reinstall. Ask the broker whether your account type allows automated trading at all — that is the actual question, and it is answerable in one support message. If you are on MetaTrader 4 rather than 5, the identical condition is reported as error 4112, AutoTrading disabled by server, and the diagnosis is the same: an account flag at the broker, not a setting on your machine.

Why this happens

MetaTrader deliberately makes automated trading opt-in at two levels, because an EA can place orders without confirmation and the platform assumes you would rather it did nothing than something unexpected. That design is sensible and it produces this exact confusion constantly.

The distinction worth learning is between "by client" and "by server" in the log message. Client means the setting is on your machine and you can change it in one click. Server means the broker has blocked it and no amount of local configuration will help.

Once trading is enabled, the next thing to verify is that the EA is actually running: its icon in the top-right corner of the chart should be blue (a smiling face in older builds and on MT4). If it is not there, see no smiley face. If it is there and still nothing happens, work through EA not taking trades.