diff --git a/www/js/app.js b/www/js/app.js
index 154381c6..93e6cceb 100644
--- a/www/js/app.js
+++ b/www/js/app.js
@@ -1467,7 +1467,9 @@ define(['jquery', 'zimArchiveLoader', 'uiUtil', 'util', 'utf8', 'cache', 'images
                             '<blockquote><code>' + err.toString() + '</code></blockquote>' +
                             "<p>If screen lock doesn't work, please change setting back to 'Normal' or try a different option.</p>");
                     } else {
-                        uiUtil.systemAlert('There was an error setting the requested orientation: ' + err.toString());
+                        uiUtil.systemAlert((!params.PWAInstalled && /iOS/.test(params.appType) ?
+                        '<p>In Safari on iOS, consider adding this app to your homescreen (Share --&gt Add to Home) isntead.</p>' : '')
+                         + '<p>There was an error setting the requested screen state:</p><blockquote><code>' + err.toString() +  '</code></blockquote>');
                         that.value = params.lockDisplayOrientation;
                     }
                     setDynamicIcons();
diff --git a/www/js/lib/uiUtil.js b/www/js/lib/uiUtil.js
index 009d9fec..b1a530b9 100644
--- a/www/js/lib/uiUtil.js
+++ b/www/js/lib/uiUtil.js
@@ -1022,7 +1022,7 @@ define(rqDef, function(util) {
             return el ? true : false; 
         }).catch(function (err) {
             console.log('Error enabling full-screen mode', err);
-            // throw err;
+            throw err;
         });
     }
     
@@ -1061,6 +1061,8 @@ define(rqDef, function(util) {
                         return 'click';
                     }
                 }
+            }).catch(function (error) {
+                throw error;
             });
         } else {
             // User wants to cancel full-screen mode and unlock the display orientation