For the proper functioning of Viafirma Fortress Desktop from the browser, it is necessary to have the appropriate extension enabled. Otherwise, the following error message is displayed: To enable the extension the following steps must be taken depending on the browser: Google Chrome Go to the extensions list installed on Google Chrome by clicking on the following link: chrome://extensions Or click on the following menu option: Locate the Viafirma Fortress Desktop extension and switch on the button to enable it: If you do not see the extension you can install it from the following link: https://chrome.google.com/webstore/detail/viafirma-fortress-desktop/gmcmomliipahkmipjohodcpbjmmaainf Internet Explorer After installing Fortress Desktop, when you open Internet Explorer a message to activate the plug-in is shown as follows: If it is not displayed you can access the list of installed plugins from the menu option: Select the 'Viafirma Fortress Desktop' plugin and press the Enable button: