diff --git a/www/common/outer/userObject.js b/www/common/outer/userObject.js
index 2ee1a1830..6ba0cd6d2 100644
--- a/www/common/outer/userObject.js
+++ b/www/common/outer/userObject.js
@@ -480,13 +480,19 @@ define([
             var next = function () {
                 var copy = JSON.parse(JSON.stringify(files));
                 exp.reencrypt(config.editKey, config.editKey, copy);
-                Object.keys(copy).forEach(function (k) {
-                    files[k] = copy[k];
-                });
-                files.version = 2;
-                delete files.migrateRo;
+                setTimeout(function () {
+                    if (files.version >= 2) {
+                        // Already migrated by another user while we were re-encrypting
+                        return void cb();
+                    }
+                    Object.keys(copy).forEach(function (k) {
+                        files[k] = copy[k];
+                    });
+                    files.version = 2;
+                    delete files.migrateRo;
 
-                onSync(cb);
+                    onSync(cb);
+                }, 1000);
             };
             onSync(next);
         };
diff --git a/www/common/userObject.js b/www/common/userObject.js
index 1c58ff831..57c1a1e6e 100644
--- a/www/common/userObject.js
+++ b/www/common/userObject.js
@@ -61,7 +61,7 @@ define([
             // Href exists and is encrypted
             var d = cryptor.decrypt(pad.href);
             // If we can decrypt, return the decrypted value, otherwise continue and return roHref
-            if (d.indexOf('#') !== -1) {
+            if (d && d.indexOf('#') !== -1) {
                 return d;
             }
         }
@@ -69,7 +69,7 @@ define([
     };
 
     module.reencrypt = function (oldKey, newKey, obj) {
-        obj = obj || {};
+        if (!obj) { return void console.error("Nothing to reencrypt"); }
         var oldCryptor = createCryptor(oldKey);
         var newCryptor = createCryptor(newKey);
         Object.keys(obj[FILES_DATA]).forEach(function (id) {
@@ -78,6 +78,7 @@ define([
             // "&& data.roHref" is here to make sure this is not a "file"
             if (data.href && data.roHref && !data.fileType) {
                 var _href = (data.href && data.href.indexOf('#') === -1) ? oldCryptor.decrypt(data.href) : data.href;
+                if (!_href) { return; }
                 data.href = newCryptor.encrypt(_href);
             }
         });
@@ -86,6 +87,7 @@ define([
             // If this folder has a visible href, encrypt it
             if (data.href) {
                 var _href = (data.href && data.href.indexOf('#') === -1) ? oldCryptor.decrypt(data.href) : data.href;
+                if (!_href) { return; }
                 data.href = newCryptor.encrypt(_href);
             }
         });
@@ -94,6 +96,7 @@ define([
             // If this folder has a visible href, encrypt it
             if (data.href) {
                 var _href = (data.href && data.href.indexOf('#') === -1) ? oldCryptor.decrypt(data.href) : data.href;
+                if (!_href) { return; }
                 data.href = newCryptor.encrypt(_href);
             }
         });