MT5 Expert Advisor Not Showing in Navigator: Eight Checks in Order, With a Decision Table

How the Navigator decides what to list

The Navigator is a view of folders on disk. MetaQuotes describes the three main program types as Expert Advisors, custom indicators and scripts, stored in the /MQL5/Experts, /MQL5/Indicators and /MQL5/Scripts folders of the platform. Inside those folders you can sort applications into subfolders, and the Navigator shows the same structure. So the question is never really why the Navigator hides your EA. It is whether the right file is in the right folder of the right terminal.

That last part trips people up. The platform keeps its editable files, including the MQL5 folder, in a data folder under your Windows user profile, and only the read-only program files in the install folder. An EA copied next to terminal.exe in Program Files is somewhere the Navigator does not read.

Check 1: Are you looking at the right terminal?

Many traders have more than one MT5 on the same PC: one from the broker, one from a prop firm, one from a download page. Each install has its own data folder, because the instance ID in the folder name is generated from the install path. An EA copied into one is invisible in the others. Look at the title bar of the terminal you are using to see which account it is logged into, then use File > Open Data Folder from that window and not from a shortcut or an old Explorer window.

Portable mode is the other way to end up in the wrong place. If the terminal was started with the /portable key, it stores its data in the installation folder instead of the user profile. In that case the MQL5 folder sits beside terminal.exe. File > Open Data Folder still takes you to the correct place, which is why it is the one method worth trusting. Also note that two copies of the platform cannot run from the same directory, so separate installs are the normal way to run several terminals.

Check 2: Is the file in MQL5\Experts?

Inside the data folder, open MQL5, then Experts. The EA file should be there or in a subfolder of it. Two near misses are common. The first is putting the file in MQL5\Indicators or MQL5\Scripts, where it will appear under Indicators or Scripts in the Navigator, if it appears at all. The second is a double-nested folder from unzipping, such as Experts\MyEA\MyEA\MyEA.ex5, which still lists but is easy to overlook.

Check 3: Is it a compiled .ex5 file?

MetaQuotes documents that compiling an MQL4/MQL5 source file produces the executable (.EX4 or .EX5) that can be launched in the platform. The .mq5 file is source code. The .ex5 file is the program. A vendor who sends you only a .mq5 file expects you to compile it, and a vendor who sends only a .ex5 file expects you to drop it straight into the Experts folder.

• .ex5 only: copy it to MQL5\Experts. It needs no compiling.
• .mq5 only: copy it to MQL5\Experts, open it in MetaEditor (press F4 in the terminal, or open the file from MetaEditor's Navigator), and press F7 to compile. If compiling succeeds, the .ex5 is created in the same folder as the .mq5.
• .ex4 or .mq4: this is an MT4 program. MQL4 and MQL5 are different languages, and MQL5.community's own migration guide says MQL4 programs have to be converted to MQL5 to be used in MetaTrader 5. Ask the vendor for the MT5 version. For the difference between the platforms, see MT4 vs MT5 for Expert Advisors.
• .mqh files: these are include files, not EAs. They belong in the folder the EA expects, usually MQL5\Include, and they never appear in the Navigator as something you can run.

Check 4: Did the compile actually succeed?

If you compiled a .mq5 and no .ex5 appeared, read the Errors tab in MetaEditor's Toolbox window. MetaQuotes states that no executable is created when compilation errors occur, while warnings still produce a file. A common reason is a missing include file or library that the source expects to find in MQL5\Include or MQL5\Libraries. Copy those files from the vendor's package, keeping their folder structure, and compile again. Do not edit code you do not understand. If the errors point into the vendor's own code, send them the log text and ask for a compiled build.

Check 5: Expand the subfolders

Folders in the Navigator are collapsed by default. If the vendor's package put the EA in a subfolder such as Experts\VendorName, expand it. The Navigator mirrors the disk structure, so the EA is listed exactly where it sits on disk.

Check 6: Refresh the view

Files copied into the MQL5 folder while the terminal is open do not always show up immediately. MetaEditor's Navigator has a Refresh command (F5) and picks up changes made in Windows Explorer automatically. For the terminal's own Navigator, right-click inside it and look for a refresh command in the context menu, since the options can differ between builds. If nothing changes, close the terminal completely and start it again, which makes it read the folders from scratch. Check the Navigator again before moving on.

Check 7: Listed but greyed out, or will not start

If the EA is in the Navigator but will not attach or run, the journal will tell you why. Open the Toolbox window and read the Experts tab (running programs) and the Journal tab (platform events). Two documented cases are worth knowing.

• CPU architecture: if a program was compiled for a newer processor instruction set than your CPU supports, MetaQuotes says the platform log prints a message that starts "your CPU architecture does not allow to run the file" followed by the file name and the instruction set required. The fix is a build compiled for your processor, which only the vendor or source owner can supply.
• DLL imports: if an application uses a DLL and DLL imports are not allowed, the OK button is not displayed in the start window. Enable it only for software from a source you trust. MetaQuotes warns that DLLs from unknown sources can cause damage.

If the EA attaches fine but places no trades, that is the Algo Trading switch, not the Navigator. See EA not trading: Algo Trading disabled. For wider symptoms, fixing common MT5 EA errors covers the rest. For 32-bit and 64-bit questions, the MQL5 reference documents a terminal property that reports whether the terminal is 64-bit, but MetaQuotes does not say that bitness changes what the Navigator lists. If a vendor says their file needs a particular bitness, ask which one and read the Experts tab.

Check 8: Antivirus or permissions removed the file

Security software sometimes quarantines unfamiliar executables. MetaQuotes does not document this behavior, so treat it as something to check. Open your security software's protection history or quarantine list and look for the EA's file name. If it is there, ask the vendor to confirm the file is genuine before restoring it. Never turn protection off to make an EA load, and never restore a file you cannot trace to its source. See the EA buying checklist before running anything unfamiliar.

Decision table: symptom, likely cause, fix

Worked example: find the right folder and confirm the EA loads

Assume you downloaded a ZIP containing MyEA.ex5 and installed MT5 twice over the years, so you are not sure which terminal is the live one. Here is the sequence that settles it. Do it on a demo account first.

1. 1

   Step 1: Close every terminal except the one you will use

   Start only the terminal logged into your demo account. Two copies cannot run from the same directory, and having extras open is how files end up in the wrong place.

2. 2

   Step 2: Open the data folder from that window

   Click File, then Open Data Folder. Explorer opens at a path that normally looks like C:\Users\yourname\AppData\Roaming\MetaQuotes\Terminal\ followed by a long ID, or at the install folder if the terminal runs in portable mode.

3. 3

   Step 3: Confirm it is the right install

   Open origin.txt in that folder. It holds the path of the install folder that belongs to this data folder. If that is not the install you launched, you opened a stale window, so go back to step 2 from the correct terminal.

4. 4

   Step 4: Copy the file into MQL5\Experts

   Go to MQL5, then Experts, and paste MyEA.ex5. If the ZIP also had .mqh include files or a Libraries folder, keep their folder names and place them under MQL5 as the vendor describes.

5. 5

   Step 5: Make the Navigator re-read the folders

   Return to the terminal. If the Navigator is hidden, show it from the View menu. Expand Expert Advisors, then any subfolders. If MyEA is not listed yet, use the refresh command in the Navigator menu if there is one, or close and reopen the terminal.

6. 6

   Step 6: Confirm it loads, not just lists

   Drag MyEA onto a demo chart and click OK in the properties window. A successfully started EA shows its name in the upper right corner of the chart. Open the Experts tab of the Toolbox and read the lines for MyEA. A line that mentions the file name, a CPU architecture, or a DLL points to one of the checks above.

If this works on demo, the problem was location, not the EA. Next, make sure it is allowed to trade, and run it on demo through your first sessions. The full routine is in how to install an EA in MT5 and how to use an Expert Advisor in MT5.