diff --git a/customize.dist/translations/messages.fr.js b/customize.dist/translations/messages.fr.js
index 0dedf52ef..3b88a26ab 100644
--- a/customize.dist/translations/messages.fr.js
+++ b/customize.dist/translations/messages.fr.js
@@ -162,6 +162,7 @@ define(function () {
     out.tags_searchHint = "Commencez une recherche par # dans votre CryptDrive pour retrouver vos pads par mot-clé.";
     out.tags_notShared = "Vos mots-clés ne sont pas partagés avec les autres utilisateurs.";
     out.tags_duplicate = "Mot-clé déjà présent : {0}";
+    out.tags_noentry = "Vous ne pouvez pas ajouter de mots-clés à un pad supprimé!";
 
     out.slideOptionsText = "Options";
     out.slideOptionsTitle = "Personnaliser la présentation";
diff --git a/customize.dist/translations/messages.js b/customize.dist/translations/messages.js
index a3e254fbe..ba55838a9 100644
--- a/customize.dist/translations/messages.js
+++ b/customize.dist/translations/messages.js
@@ -164,8 +164,8 @@ define(function () {
     out.tags_searchHint = "Find files by their tags by searching in your CryptDrive";
     out.tags_searchHint = "Start a search with # in your CryptDrive to find your tagged pads.";
     out.tags_notShared = "Your tags are not shared with other users";
-
     out.tags_duplicate = "Duplicate tag: {0}";
+    out.tags_noentry = "You can't tag a deleted pad!";
 
     out.slideOptionsText = "Options";
     out.slideOptionsTitle = "Customize your slides";
diff --git a/www/common/sframe-common-interface.js b/www/common/sframe-common-interface.js
index 97fcc9fb6..422b76bfe 100644
--- a/www/common/sframe-common-interface.js
+++ b/www/common/sframe-common-interface.js
@@ -31,7 +31,12 @@ define([
     UI.updateTags = function (common, href) {
         var sframeChan = common.getSframeChannel();
         sframeChan.query('Q_TAGS_GET', href || null, function (err, res) {
-            if (err || res.error) { return void console.error(err || res.error); }
+            if (err || res.error) {
+                if (res.error === 'NO_ENTRY') {
+                    Cryptpad.alert(Messages.tags_noentry);
+                }
+                return void console.error(err || res.error);
+            }
             Cryptpad.dialog.tagPrompt(res.data, function (tags) {
                 if (!Array.isArray(tags)) { return; }
                 sframeChan.event('EV_TAGS_SET', {
diff --git a/www/common/userObject.js b/www/common/userObject.js
index 8a3662a7b..658a0243c 100644
--- a/www/common/userObject.js
+++ b/www/common/userObject.js
@@ -499,7 +499,6 @@ define([
             });
         };
         var spliceFileData = exp.removeData = function (id) {
-            files[FILES_DATA][id] = undefined;
             delete files[FILES_DATA][id];
         };
 
@@ -649,7 +648,6 @@ define([
                 var hash = f.indexOf('#') !== -1 ? f.slice(f.indexOf('#') + 1) : null;
                 if (hash && key.indexOf(hash) === 0) {
                     debug("Deleting pad attribute in the realtime object");
-                    files[key] = undefined;
                     delete files[key];
                 }
             });
@@ -709,7 +707,6 @@ define([
                 var parentPath = path.slice();
                 var key = parentPath.pop();
                 var parentEl = find(parentPath);
-                parentEl[key] = undefined;
                 delete parentEl[key];
             });
 
@@ -728,7 +725,6 @@ define([
                     return;
                 }
                 // Trash but not root: it's just a tree so remove the key
-                parentEl[key] = undefined;
                 delete parentEl[key];
             });
             deleteMultipleTrashRoot(trashRoot);
@@ -767,7 +763,6 @@ define([
                     return;
                 }
                 parentEl[newName] = element;
-                parentEl[oldName] = undefined;
                 delete parentEl[oldName];
                 if (typeof cb === "function") { cb(); }
                 return;
@@ -777,7 +772,6 @@ define([
             var data = files[FILES_DATA][element];
             if (!data) { return; }
             if (!newName || newName.trim() === "") {
-                data.filename = undefined;
                 delete data.filename;
                 if (typeof cb === "function") { cb(); }
                 return;
@@ -899,9 +893,7 @@ define([
                                 delete parent[okey];
                             });
                         });
-                        files[OLD_FILES_DATA] = undefined;
                         delete files[OLD_FILES_DATA];
-                        files.migrate = undefined;
                         delete files.migrate;
                         console.log('done');
                         todo();
@@ -942,7 +934,6 @@ define([
                 for (var el in element) {
                     if (!isFile(element[el], true) && !isFolder(element[el])) {
                         debug("An element in ROOT was not a folder nor a file. ", element[el]);
-                        element[el] = undefined;
                         delete element[el];
                         continue;
                     }
@@ -994,11 +985,9 @@ define([
                 for (var el in tr) {
                     if (!Array.isArray(tr[el])) {
                         debug("An element in TRASH root is not an array. ", tr[el]);
-                        tr[el] = undefined;
                         delete tr[el];
                     } else if (tr[el].length === 0) {
                         debug("Empty array in TRASH root. ", tr[el]);
-                        tr[el] = undefined;
                         delete tr[el];
                     } else {
                         toClean = [];