How to Fix ‘DLL Calls Are Not Allowed’ Error in MT5 EA

Summary: Your MT5 Expert Advisor fails to load with a DLL error. This guide walks you through enabling DLL imports in MT5 settings, plus a security tip for safe trading.




Step 1: Identify the DLL Error Message

Attach your EA to an MT5 chart. If a red error appears in the ‘Experts’ tab saying ‘DLL calls are not allowed’ or ‘cannot load because DLL imports are disabled’, you have this issue. Screenshot: Experts tab showing red DLL error text.

Step 2: Open MT5 Settings

Click ‘Tools’ in the top menu bar. Then select ‘Options’ from the dropdown (or press Ctrl+O on Windows / Cmd+O on Mac via Wine). Screenshot: Tools menu with Options highlighted.

Step 3: Go to Expert Advisors Tab

In the Options window, click the ‘Expert Advisors’ tab. You will see several permission checkboxes. Screenshot: Expert Advisors tab with all options visible.

Step 4: Allow DLL Imports

Check the box that says ‘Allow DLL imports’. Also check ‘Allow WebRequest for listed URLs’ only if your EA needs internet access. Leave ‘Confirm DLL function calls’ checked if you want a security prompt each time. Screenshot: Allow DLL imports checkbox checked.

Step 5: Click OK and Restart MT5

Click ‘OK’ to save settings. Completely close MT5 (right-click the taskbar icon and select ‘Exit’). Then reopen MT5 and re-attach your EA. The DLL error should disappear. Screenshot: MT5 reopened with EA running normally.

Security Note: Only enable DLL imports for EAs from trusted developers. Malicious DLLs can access your system. If unsure, keep ‘Confirm DLL function calls’ enabled to see what the EA requests.

Reference: MetaQuotes Help Desk – MT5 Expert Advisors Security Settings.