Allow WebRequest or allow DLL in MetaTrader 4

What is causing it

WebRequest URLs and DLL imports are blocked by default for safety.

Why this happens

MT4 blocks both outbound internet requests and external DLL calls from indicators and Expert Advisors by default. Anything you attach to a chart is code running on your machine with access to your account, so the platform requires you to grant these permissions deliberately rather than assuming them. The web permission is an allowlist of specific addresses you control; the DLL permission is broader, because DLL code runs outside the platform entirely with your Windows user's rights, and cannot be inspected or restrained by MT4.

Both permissions are read when a program starts, not continuously, so changing the setting while the tool is attached does nothing until you remove and re-attach it. The address check is also literal, so an entry that differs even slightly from the address the tool requests will leave it blocked while looking correct at a glance.

The fix, step by step

1. Open Tools, Options, Expert Advisors.
2. Tick "Allow WebRequest for listed URL" and add the exact URL.
3. For DLLs, tick "Allow DLL imports", and only for tools you trust.
4. Re-attach the tool to the chart.

How to confirm it is fixed

Re-attach the tool and read the Experts tab. The permission message should be gone and the tool should complete whatever it needed the access for, such as a licence check or a data pull. Any on-chart status the tool shows should change from an error state to a working one.

Stopping it happening again

Add the address as part of installing a tool that needs internet access, before you attach it, and copy it exactly from the tool's instructions. Treat the DLL permission as a much bigger decision than the web one and grant it only to software from a source you would trust with access to your computer, turning it off again when you stop using that tool.