MT5 expert advisor installation guide: copy the file, attach it to a chart and verify it loaded

How to install an MT5 expert advisor and confirm it works

To install an MT5 expert advisor, open MetaTrader 5, go to File > Open Data Folder, copy the EA file into MQL5 > Experts, refresh the Navigator, then drag the EA onto a chart and allow Algo Trading in both the EA window and the terminal. The install is only finished once the Experts tab prints a line saying the EA loaded on the chart you chose. This guide covers each step and the checks that show you whether the EA actually loaded, which permissions it has, and where its errors will show up.

This article stops at a clean, verified install. If the EA is running but never opens a position, use the diagnostic checklist for an MT5 expert advisor not placing trades instead.

Before you install: check what you received

Look at the files the vendor sent before you copy anything:

• .ex5 is a compiled EA. It runs as is and is what most commercial EAs ship as.
• .mq5 is source code. MetaTrader 5 needs to compile it into an .ex5 before it can run. Opening it in MetaEditor and pressing Compile does this, and any compile errors appear in MetaEditor's own error log.
• .set files are input presets. They are not installed in the Experts folder. They are loaded later from the EA's Inputs tab.
• Extra files such as custom indicators or libraries. Some EAs call indicators that must sit in MQL5 > Indicators, or libraries that must sit in MQL5 > Libraries. The vendor documentation should say so. If it does not, ask before installing.

Also check which account type the EA expects (hedging or netting) and which symbols it was built for, for example EURUSD or an index CFD that tracks NQ. Installing an EA built for one symbol on another chart will not give an error at install time, but it may behave differently later.

If you bought the EA from the built-in MQL5 Market, you can skip the copy step. Market purchases install automatically and appear under a Market subfolder in the Navigator's Expert Advisors list.

Step 1: copy the file into the MQL5 Experts folder

Every MetaTrader 5 installation has its own data folder, and that folder is often not the program folder under Program Files. Always open it from inside the terminal so you are sure you have the right one:

1. In MetaTrader 5, click File > Open Data Folder.
2. Open the MQL5 folder, then Experts.
3. Paste the .ex5 (or .mq5) file here. Creating a subfolder named after the vendor keeps things tidy, and the Navigator will show it as a folder.
4. Copy any required indicators into MQL5 > Indicators and libraries into MQL5 > Libraries, exactly as the vendor specifies.

If you run several MT5 terminals, for example one per broker, each one has its own data folder. Copying the EA into one does not install it in the others.

Step 2: refresh the Navigator

Open the Navigator with Ctrl+N or View > Navigator. Right-click Expert Advisors and choose Refresh. The EA should now be listed. If it does not appear:

• Confirm you pasted into MQL5 > Experts and not MQL5 > Indicators or the root data folder.
• If you copied an .mq5, it must compile successfully. Open it in MetaEditor and check the Errors tab.
• Restart the terminal. It rescans the folders when it starts.

Step 3: attach the EA to a chart

Open a chart of the symbol and timeframe the EA was designed for, say EURUSD H1. Then drag the EA from the Navigator onto the chart, or right-click it in the Navigator and choose Attach to a chart. Keep in mind that MT5 allows one EA per chart. If you need the same EA on EURUSD and GBPUSD, open two charts.

The EA properties window opens. Go through its tabs before clicking OK:

• Common tab: tick Allow Algo Trading if you want the EA to send orders. Without it the EA can load and calculate, but it should not be able to trade. This tab also has options related to signals and position direction, depending on your build. Read what each option says rather than accepting the defaults.
• Inputs tab: check lot size, risk and any symbol-specific values. You can load a preset here. Our guides on how to change MT5 expert advisor inputs and loading set files cover this in detail.
• Dependencies tab: this shows whether the EA imports DLLs or other modules. Only allow DLL imports for an EA from a source you trust and only if the vendor states it needs them. An EA that asks for DLL access it does not explain is a reason to stop and ask questions.

Step 4: set Algo Trading permissions at the terminal level

The EA checkbox alone is not enough. MetaTrader 5 has three layers of permission, and all of them have to agree:

1. Terminal options: Tools > Options > Expert Advisors. Check that algorithmic trading is allowed. This tab also contains DLL and WebRequest permissions, plus options that disable algorithmic trading automatically when you change accounts or profiles. If you switch between a demo and a live account, those options can turn algo trading off without you noticing.
2. Toolbar button: the Algo Trading button on the main toolbar is a global switch. When it is off, no EA in the terminal can trade, whatever its own settings say.
3. EA properties: the Allow Algo Trading box on the Common tab, set per chart.

If the EA needs WebRequest, for example to call a news or license server, the exact URL has to be added to the allowed list in Tools > Options > Expert Advisors. The vendor should give you that URL. MetaQuotes documents these switches on the algorithmic trading help page.

Step 5: verify the EA loaded and has the permissions you intended

This is the step most installs skip. Check three places.

The chart itself

After attaching, the EA name appears in the top-right corner of the chart with a small icon. The icon's look changes depending on whether algo trading is permitted. Compare it before and after you toggle the toolbar Algo Trading button, and you will see what the active and inactive states look like on your build. Hovering over the icon or right-clicking the chart and opening Expert Advisors > Properties also lets you reopen the settings window to confirm what you set.

The Experts tab

Open the Toolbox with Ctrl+T and select the Experts tab. A successful install prints a line that names the EA, the symbol and the timeframe, along the lines of the EA loaded successfully on EURUSD,H1. Many EAs also print their own startup messages here, such as input values or a version number. If the EA writes an initialization error or removes itself, the reason usually appears on this tab.

The Journal tab

The Journal records terminal-level events: connection, account login, and messages about algo trading being enabled or disabled. If the Experts tab looks fine but something still feels off, read the Journal lines with the same timestamp. For a full walkthrough of what these messages mean, see MT5 expert advisor log errors explained.

Make errors visible from day one

An EA that fails silently is worse than one that fails loudly. A few habits keep problems on screen:

• Keep the Toolbox open on the Experts tab while the EA runs, at least for the first sessions.
• Right-click inside the Experts tab to open the log folder. Daily log files are stored there, so you can check what happened while you were away.
• Set up notifications if the vendor supports them. MetaTrader 5 can send push notifications to the mobile app once you enter your MetaQuotes ID in Tools > Options > Notifications, and some EAs use this to report errors.
• After any terminal update, restart, or account switch, recheck the chart icon and the toolbar button. Permissions can change after these events depending on your settings.

MetaQuotes lists the general workflow for robots and indicators on the trading robots and indicators help page, which is worth reading once.

Install on a demo account first

Run every new EA on a demo account before connecting it to real money, even if the install looks clean. A demo run shows you whether the EA's startup messages, symbol handling and permissions behave as documented with your broker's contract specifications. A correct installation says nothing about whether the strategy is suitable for you, and automated trading carries the same market risk as manual trading. The CFTC's customer advisory on automated trading systems is a useful read on that point.

Conclusion

A complete MT5 expert advisor installation has five parts: the right file in MQL5 > Experts, a refreshed Navigator, the EA attached to the intended symbol and timeframe, permissions aligned across terminal options, the toolbar button and the EA window, and a confirmed load message in the Experts tab. Check each one and you will know the EA is running with the permissions you chose and that its errors will be visible when they happen. If you would rather start from an EA that ships with documented inputs and set files, the MT5 expert advisor page explains what is included. You can explore the documented MT5 expert advisor available at SierraOnShop.

FAQ

Do I need to restart MetaTrader 5 after copying an EA?

Usually not. Right-clicking Expert Advisors in the Navigator and choosing Refresh is enough. Restart only if the EA still does not appear after a refresh.

Can I run the same EA on several charts at once?

Yes. Attach it to a separate chart for each symbol or timeframe. Each chart holds one EA with its own inputs, so check that the settings on each chart match what you intend, especially lot size.

Why did the EA disappear from my chart right after attaching it?

The EA most likely stopped during initialization. Look at the Experts tab for the message printed at that moment, which often points to a missing indicator, an unsupported symbol or a license check.

Where do I put the .set file that came with the EA?

Not in the Experts folder. Load it from the Inputs tab of the EA properties window with the Load button, then confirm the values match the EA version you installed.

How do I uninstall an EA cleanly?

Remove it from every chart first, then delete the file from MQL5 > Experts and any indicators or libraries that came with it, and refresh the Navigator.