<ul><li>Fixed <strong>Undefined array key "EventEndTime"</strong> in upcoming/past/canceled_events_data.php — added ?? null-safe guard on EventEndDate/EventEndTime/EventStartDate/EventStartTime</li><li>Fixed <strong>Undefined variable $rsDomain</strong> in all 3 event tab headers — now uses $rsDomain ?? $_SESSION["LIVE_SITE_NAME"] ?? ""</li><li>Fixed <strong>Undefined variable $ModuleName</strong> in all 3 event tab headers — added ?? "" guard</li><li>Fixed <strong>JS TypeError: response.EventStartDate.format() is not a function</strong> in platform/module/EventsManager/js/custom_js.php lines 267-268 — EventStartDate/EndDate are plain PHP strings, not moment.js objects; removed .format() call</li><li>Applied same JS .format() fix to platform/services/websites/modules/module/EventsManager/js/custom_js.php</li><li>Changed async:false to async:true on 2 AJAX calls in services module EventsManager custom_js.php (deleteLiveMeet, getAVideoUserGroups)</li><li>Backups created: upcoming_events_data-bk-v3.php, past_events_data-bk-v3.php, canceled_events_data-bk-v3.php, custom_js-bk-v3.php (both locations)</li><li>Post-fix validation: 0 PHP errors, 0 JS application errors, 0 network failures. All 3 tabs render clean. Add Event modal opens correctly.</li></ul>