1. Validation of .xxe_gui files

GUI specification files may be written using XMLmind XML Editor[3] or using a text editor.

If you use a text editor, do not forget to validate your GUI specification against its schema. After downloading and installing the add-on called "XMLmind XML Editor Configuration Pack" using OptionsInstall Add-ons, this schema is found in XXE_user_preferences_dir/addon/xxe_config_pack/gui/xsd/gui.xsd. Linux example:

~/.xxe7/addon$ /opt/xxe/bin/xmltool validate \
    -s ~/.xxe7/addon/xxe_config_pack/gui/xsd/gui.xsd customize.xxe_gui


[3] You'll need to download and install the add-on called "XMLmind XML Editor Configuration Pack" in order to do that.