Fixing the MetaTrader WebRequest Error When Adding License Validation

If you've just protected an EA and it's throwing a WebRequest-related error the first time it runs, this is almost certainly why: MetaTrader blocks outbound HTTP requests by default, for every EA, regardless of who wrote it or how it's licensed.

This isn't a bug in the EA — it's MetaTrader's own default security posture, and it applies to any Expert Advisor that calls out to a URL, license validation included.

The fix

In MetaTrader:

Tools → Options → Expert Advisors → "Allow WebRequest for listed URL"

Add the validation URL to the allowed list, tick the box, and restart the EA. That's the entire fix — it's a one-time setting per install, not something that needs repeating on every chart or every restart of the terminal.

Why this catches people off guard

It's easy to miss because nothing about writing or compiling the EA warns you it's coming — the error only shows up at runtime, on the machine actually running MetaTrader, which is often your customer's machine, not yours. If you don't mention it up front, a customer's first experience with your protected EA can be an error message that reads like the software is broken.

The practical fix: mention it once, in whatever instructions ship with the EA. Something as short as "first run may ask you to allow the validation URL under Tools → Options → Expert Advisors — this is a one-time MetaTrader setting, not an error with the EA" heads off almost every support message about it before it happens.

If you built the protection yourself

If you inserted your own validation call rather than using a wizard that does it for you, double check you're calling WebRequest() (not a raw socket or a third-party HTTP library) — WebRequest() is the only outbound call MetaTrader's allow-list mechanism actually covers. Anything else will fail in a way this setting can't fix.