AT Command Tester is a Java applet, sometimes the cached version of the application gets loaded in the browser. This might prevent users from accessing the latest version of the tool. In order to clear the AT Command Cache, please follow the steps below,
New re-start your web browser and clear the web browse cache. Re-load the At Tester Application – https://m2msupport.net/m2msupport/module-tester/ .