Six symptoms cover most "it's not working" reports. Find the line you see in your log — each card below is one fix.
Open your log first. Press Ctrl+T in MT5 to open the Toolbox, then click the Experts tab. Every symptom below appears there.
WhyA model selected in Group 1 has no matching key in Group 2.
FixPaste the missing key and re-attach. Key guide →
WhyThe provider's URL is not whitelisted in MT5.
FixTools → Options → Expert Advisors → add the URLs, then re-attach. URL list →
WhyKey invalid, revoked, or pasted with stray spaces / line breaks.
FixRe-copy the key from the provider console into the matching Group 2 field.
WhyToo many calls on one key — a free-tier limit, or other apps sharing the key.
FixDrop Analysis depth to Fast, step up the provider tier, or move one seat to another provider.
WhyNo EAs are currently trading, or Target mode is on specific magics with a wrong list.
FixConfirm your other EAs are running, then switch to Whole account or fix the magic list.
WhyThe AutoTrading toolbar button is off, or Allow Algo Trading is unticked on the Common tab.
FixEnable both, then re-check. In Shadow mode this is expected — Shadow never touches the broker.