diff --git a/app/index.html b/app/index.html
index af6b645..9ac8e70 100644
--- a/app/index.html
+++ b/app/index.html
@@ -2653,6 +2653,24 @@ function fmtDatetime(dtStr) {
     const contentEl = document.getElementById('pageContent');
     highlightNav(file);
 
+    // If the active category is "hidden" (no notfoundmessage, not visibilityifnocontent:visible)
+    // and this page has no variant for it, silently switch to the default category instead of
+    // showing an error.
+    if (categoriesUse && activeCategory !== defaultCategoryCode && file !== defaultPage()) {
+      const cat = categoriesByCode[activeCategory];
+      const isHidden = cat && !cat.notfoundmessage && cat.visibilityifnocontent !== 'visible';
+      if (isHidden) {
+        const pageEntry = navData.find(p => p.file === file);
+        const hasVariant = !pageEntry || pageEntry.uncategorized
+          || !(pageEntry.variants && pageEntry.variants.length)
+          || pageEntry.variants.includes(activeCategory);
+        if (!hasVariant) {
+          setActiveCategory(defaultCategoryCode);
+          return;
+        }
+      }
+    }
+
     // Build a clean URL: keep origin + path, set ?cat only when non-default, set hash to conceptual file
     const u = new URL(window.location);
     if (categoriesUse && activeCategory && activeCategory !== defaultCategoryCode) {
@@ -2667,7 +2685,7 @@ function fmtDatetime(dtStr) {
 
     const result = await fetchPageFile(file);
     if (!result.ok) {
-      const offlineMsg = localStorage.getItem('mdcms-offline');
+      const offlineMsg = !navigator.onLine && localStorage.getItem('mdcms-offline');
       const bodyMsg = offlineMsg
         ? `<p>${offlineMsg}</p>`
         : `<p>${pageNotFoundMessage()}</p>`;