<h4>Groups Detail Page — SyntaxError & Warning Fixes</h4><ul><li><strong>CRITICAL Fixed:</strong> SyntaxError at line 6665 — PHP warning for undefined <code>$_GET['postid']</code> injected into JS <code>const _POSTID = '...'</code>, breaking all JS after that point. Added <code>?? ''</code> (newsfeed_js.php:12).</li><li><strong>CRITICAL Fixed:</strong> SyntaxError at line 9259 — undefined <code>$webdetails</code> variable injected PHP warning into JS <code>var follow_feature = '...'</code>. Fixed both occurrences (lines 43, 2603) with <code>isset()</code> guard.</li><li><strong>Fixed:</strong> Undefined <code>$_GET['action']</code> in newsfeed_section.php lines 57-59 — added <code>?? ''</code> on all 3 select option comparisons.</li><li><strong>Fixed:</strong> Undefined <code>$_GET['action']</code> in group_details.php switch statement (line 232) — added <code>?? ''</code>.</li><li><strong>Fixed:</strong> Undefined <code>$my_name</code> in newsfeed_js.php:56 — variable only set in view_post.php but used in shared JS. Added <code>isset()</code> guard.</li><li><strong>Fixed:</strong> Null property access <code>$ipdata->geoplugin_countryName</code> in group_details.php:289 — GeoIP lookup returned null. Added <code>isset()</code> guard.</li><li><strong>Fixed:</strong> Hardcoded <code>$data[9]</code> array index in newsfeed_member.class.php:154 — crashed when fewer than 10 posts existed. Changed to use <code>count($data) - 1</code> dynamically.</li></ul><p><strong>Files:</strong> newsfeed_js.php, newsfeed_section.php, group_details.php, newsfeed_member.class.php</p><p><strong>Result:</strong> Group detail page: 18,638 lines, 0 PHP warnings, 0 JS SyntaxErrors.</p>