Nine symptoms cover almost every broken setup. 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.
WhyYour prompt file didn't load at all.
FixFind the PromptLibrary entries in the Experts tab, then re-save the file as ANSI.
WhyThe NAME= line is missing inside a [PRESET] block.
FixAdd it — NAME is required and must be under 30 characters.
WhyA STRATEGY_END, RULES_END or [/PRESET] is missing.
FixClose the block — every _BEGIN needs its _END.
WhyMarkers are indented, or the file is in the wrong encoding.
FixMove all markers to column 0 and re-save as ANSI.
WhyA UTF-8 BOM or non-ASCII characters slipped into the file.
FixSave as ANSI. Strip diacritics, smart quotes and em-dashes.
WhyAn agent selected in Group 1 / 1C has no matching API key in Group 1B.
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 1B field.
WhyToo many calls on one key — several charts sharing it, or a free-tier limit.
FixRaise the update interval, step up the provider tier, or split agents across providers.