Hello and welcome on forums.
Hope these crash isn't too serious
In
Liberkey\LiberkeyTools\LiberkeyMenu\data\Menu you can find a directory name
bak.
In it, you have some backups.
Close your liberkey ; rename your actual
default.xml for example
default_crashed.xml, then go in
Liberkey\LiberkeyTools\LiberkeyMenu\data\Menu\bak, copy one of the file like
default_2012-11-29_00-36-27.xml and then rename it
default.xml.
After, try restart your Liberkey.
It's possible you have to restore too
myapps.xml ;
recent.xml ;
quicklaunch.xml like for default.xml
Hope your Liberkey could be totally restored.
JP4U