Translations:Theme editor/16/en
From LimeSurvey Manual
Permissions Note: on unix/linux systems, these theme files will be owned by the group and user where the web server is running (may be "www" for some systems). So, make sure you have the proper permisisons to edit these files, When you save them, make sure they don't change ownership! This way, you can still use the web Theme Editing interface if needed.