EA does not appear in the MT5 Navigator

Causes, most likely first

1. It was copied to the installation folder rather than the data folder

MetaTrader reads EAs from a per-user data folder, not from Program Files. Open File → Open Data Folder inside MetaTrader — this always opens the correct location — then place the file in MQL5\Experts. Copying to the installation directory does nothing, and it is the single most common cause.

2. The Navigator has not been refreshed

MetaTrader scans for new files on startup and on demand. Right-click inside the Navigator and choose Refresh, or restart the terminal. A file copied while the terminal is open will not appear on its own.

3. The file is the wrong type for this platform

MT5 loads .ex5 and .mq5 files. An .ex4 file is an MT4 program and will never appear in MT5 — the two platforms are not compatible, and no conversion tool changes that. See MT4 vs MT5.

4. The file is blocked by Windows

Files downloaded from the internet can carry a security flag that prevents them loading. Right-click the file, open Properties, and tick Unblock if the option is present.

Why this happens

The data folder confusion exists because MetaTrader can be installed once and run as several instances with separate data folders, particularly when multiple broker terminals are installed. The File menu route is the only one that is always correct.

On a VPS this trips people up more often, because the natural instinct is to copy the file to wherever the shortcut points. That is the installation directory.

Once the EA appears in the Navigator, drag it onto a chart and check for the smiling face — see no smiley face if it does not appear.