Summary: This tutorial details the process of diagnosing and fixing the "DLL import error" when running an EA on MT4, with specific differences between Windows 10 and Windows 11 environments and VPS hosting.




A few weeks back, I was migrating a client's trading robot from a local Windows 10 machine to a Windows 2022 VPS. The EA compiled fine locally, but the moment I attached it to the chart on the server, the journal spat out that dreaded "DLL import error" (error 147). The funny thing is, the exact same file worked perfectly on my desktop.

The knee-jerk reaction is always to check the obvious: "Allow DLL imports" checkbox. It was ticked. So, I dove into the real troubleshooting.

First, I checked the Experts folder to ensure the DLL file was actually present. It was. But the EA was looking for a specific version. This is where the MQL5 documentation on Dynamic Libraries comes in handy. The docs clearly state that the import function name must match exactly.

However, the hidden killer here is dependency. The EA's DLL wasn't just a standalone file; it relied on the Microsoft Visual C++ Redistributable. On Windows 10, it was already installed. On a fresh Windows 2022 VPS, it wasn't. Installing the latest VC++ Redistributable (both x86 and x64, as MT4 is 32-bit) solved the silent crash for most EAs.

But one specific EA kept failing. I traced it to the KERNEL32.dll import for GetTickCount64. According to official Microsoft documentation, this function is supported from Windows Vista onwards. However, running the EA on a specific older Windows 2012 VPS instance gave a "missing entry point" error. My exclusive insight here is that MetaTrader 4, being a 32-bit application, utilizes a "side-by-side" assembly model on newer OS. The official docs don't mention this, but I found that placing the required DLL directly into C:\Windows\SysWOW64 (not System32) and running the VPS terminal as Administrator fixed this specific "entry point" issue, whereas placing it in the Experts folder failed.

Another common pitfall is Windows Defender or the VPS anti-virus quarantining the DLL silently. You don't get an error popup, the file just vanishes. I had to add the entire MetaTrader folder as an exclusion.

The Operational Fix List:
  • <strong>Verify File Integrity:</strong> Check if the .ex4 and .dll are in MQL4\Experts and MQL4\Libraries respectively.

  • <strong>Enable Settings:</strong> In Navigator, right-click the EA > Properties > "Allow DLL imports" and "Allow WebRequest" if needed.

  • <strong>Check C++ Runtimes:</strong> Install the latest Visual C++ Redistributable package.

  • <strong>VPS Specific:</strong> If running on a VPS with Windows Server, ensure Desktop Experience is installed (often missing and required for specific graphic-related DLL calls).

  • <strong>The "Path" Issue:</strong> My unique solution for stubborn EAs is to use #pragma comment(lib, "mylib.lib") in the source code if you have it, or as a workaround, register the DLL using regsvr32 if it's a COM object.


    • Reference: MQL5 Documentation - Dynamic Libraries (docs.mql5.com), Microsoft Docs - KERNEL32.dll Library.

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