diff --git a/HISTORY.md b/HISTORY.md
index ec3b57e957..33bac078de 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -3,6 +3,7 @@
 ## v4.2.2.9
 ### 2018-11-29
 * GUI: prepared release
+* GUI: fixed offline version (avoid sessionStorage access)
 
 ### 2018-11-28
 * Objects: added special checks to make imporing text-based files into vars easier in Windows
diff --git a/src/gui.js b/src/gui.js
index 499d171b12..b58864e50a 100644
--- a/src/gui.js
+++ b/src/gui.js
@@ -296,12 +296,14 @@ IDE_Morph.prototype.openIn = function (world) {
         }
     }
 
-    if (!sessionStorage.username) {
-        // check whether login should persist across browser sessions
-        this.cloud.initSession(initUser);
-    } else {
-        // login only persistent during a single browser session
-        this.cloud.checkCredentials(initUser);
+    if (location.protocol !== 'file:') {
+        if (!sessionStorage.username) {
+            // check whether login should persist across browser sessions
+            this.cloud.initSession(initUser);
+        } else {
+            // login only persistent during a single browser session
+            this.cloud.checkCredentials(initUser);
+        }
     }
 
     this.buildPanes();