Dear other Members, dear Support i concider to modify the FF settings for our users. In special i want to make sure that when updating or installing a new ESR FF Version the following settings are set as post installation step as well. a.) deactivate FF embedded PDF Viewer and instead use external Acrobat PDF Viewer by default. by default that pdf viewer is available on the clients i assume that modifying the prefs.rs file to make this work? but in detail how should this be done? b.) modify the about:config setting security.insecure_field_warning.contextual.enabled and choose faulse by default. Im aware of the security issue in the recommended question b :) does anyone have a helping idea how and where to modify that parts? thanks in advance ImtheMark

// file needs to start with a comment line
lockPref("pdfjs.disabled", true);
lockPref(*security.insecure_field_warning.contextual.enabled", false);