I have had the panel started from terminal, and after 1-2 days the menu-plugin stopped working and the terminal was full of such logs: ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files ** (xfce4-menu-plugin:8453): CRITICAL **: Unable to create FrapMenu from file '/etc/xdg/menus/xfce-applications.menu': Too many open files doing lsof, led me to such output (only part of it): xfce4-men 8453 gero 24r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 32r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 40r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 48r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 56r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 64r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 72r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 80r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 88r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 96r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 104r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 112r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 122r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 130r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 138r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 146r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 154r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 162r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 170r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 178r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 186r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 194r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 202r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 210r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 218r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 226r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 234r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 242r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 250r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 258r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 266r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 274r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data xfce4-men 8453 gero 282r DIR 8,3 4096 2064428 /usr/share/xfce4/menu-data I have found out that the culprit is panel-plugin/desktop-menu-plugin.c dmp_read_config-function which does not close the file opened with rcfile = xfce_rc_simple_open(cfgfile, TRUE); I'll attach a patch, which is trivial simply adding: xfce_rc_close (rcfile); to the end of the function, resolves the problem for me.
Created attachment 1065 open-files.patch closes the opened rc-file on function exit
Fixed in svn, trunk and 4.4 branch, thanks.