MT5 no connection to trade server

Causes, most likely first

1. The connection dropped and recovered without you noticing

MetaTrader reconnects automatically, so a drop of a few minutes leaves no visible trace except a gap in the Journal. Any signal that occurred during it was missed entirely. Check the Journal tab rather than the status bar, which only shows the current state.

2. The machine slept, or Windows Update restarted it

By far the most common cause on a home computer, and it is silent. A laptop closing its lid stops trading exactly as effectively as a crash. This is the entire argument for a VPS — not latency, which barely matters for most strategies.

3. The wrong server was selected for the account

Brokers run several servers and an account belongs to exactly one. A login that fails immediately with no connection is usually the wrong server rather than a wrong password. The correct name is in the account opening email.

4. A firewall or antivirus is blocking the terminal

MetaTrader needs outbound access on the ports the broker uses. Corporate networks and some antivirus suites block it, producing a permanent no-connection state rather than an intermittent one.

Why this happens

The dangerous case is not the disconnect — it is the open position during it. The terminal cannot manage a trade it cannot see, so a stop attached at the broker will still execute but any trailing or partial-close logic in the EA will not.

That is the argument for stops living at the broker rather than in EA memory. If protection only exists inside the running program, protection stops existing when the program does.

Test the failure rather than assuming it: reboot deliberately once and confirm MetaTrader relaunched, logged back in, and the EA reattached with a smiling face. See MT5 disconnected on the VPS.