Added onerror fallback placeholders to all img tags in the GroupsManager module that were missing them. Files updated: event.php (2 event images), editGroupSection.php (1 group pic), groups.php (4 group pics - fixed misplaced onerror on div moved to img tag, added to joined/pending/invitation/carousel groups), group_details.php (2 event images), event_list.php (1 JS event image), newsfeed_section.php (3 content images - thumbnail, carousel, single), js.php (1 JS member avatar), view_post.php (5 images - favicon, embed, thumbnail, carousel, single), newsfeed_js.php (11 JS content images across thumbnail, carousel, single, and update contexts). Used context-appropriate placeholders: default-avatar.png for avatars, image_placeholder.png for group pics, noimage.png for content/general images. Used 