--- a/b/user/plugins/add-page-by-form/add-page-by-form.php	2026-07-05 12:03:55.849015242 +0200
+++ b/user/plugins/add-page-by-form/add-page-by-form.php	2026-07-05 11:55:06.175609339 +0200
@@ -619,7 +619,19 @@
                     if ($overwrite_mode !== 'false') {
                         if (file_exists($new_page_folder)) {
                             if ($overwrite_mode === 'edit') {
-                                $original_frontmatter = (array)$pages->get($new_page_folder)->header();
+                                // intotheeast patch (temporary, pending upstream fork):
+                                // On Grav 2.0 header() returns a Grav\Common\Page\Header
+                                // object whose data sits in a PROTECTED `items` property,
+                                // so the original `(array)$header` yields mangled keys
+                                // (\0*\0items) and every frontmatter lookup below misses —
+                                // `array_merge($original_frontmatter['photos'], …)` then
+                                // fatals under PHP 8. Use toArray() (clean keys) when the
+                                // Header exposes it; fall back to the cast for a plain
+                                // stdClass (classic pages).
+                                $__header = $pages->get($new_page_folder)->header();
+                                $original_frontmatter = (is_object($__header) && method_exists($__header, 'toArray'))
+                                    ? $__header->toArray()
+                                    : (array)$__header;
                             } else {
                                 Folder::delete($new_page_folder);
                             }
@@ -708,7 +720,13 @@
 
                             $file_fields_updated = array();
                             foreach ($file_fields as $file_field => $uploads) {
-                                $file_fields_updated[$file_field] = array_merge($original_frontmatter[$file_field], $uploads);
+                                // intotheeast patch: entries that render from folder-scanned
+                                // media carry no matching frontmatter key, so fall back to []
+                                // rather than fatal array_merge() on a missing/null original.
+                                $existing = (isset($original_frontmatter[$file_field]) && is_array($original_frontmatter[$file_field]))
+                                    ? $original_frontmatter[$file_field]
+                                    : array();
+                                $file_fields_updated[$file_field] = array_merge($existing, $uploads);
 
                                 // Get any (uploaded and then) deleted files
                                 foreach ($copy_files['deleted'] as $file_to_delete) {