Reset Libreoffice to default

First close Libreoffice and
uninstall it in the software centre then
login as root by going to
terminal and typing
gksudo nautilus. This allows you to navigate and change root files and folders.
Open the parent directory by going to the
home folder and in the tool bar select
Go and then select
Open parent. this opens the root folders. Now select
View and select
show hidden files, than search for
registrymodifications.xcu Now select
open item location. You should now be it
/home/computername/.config/libreoffice/4/user/registrymodifications.xcu
Select the folder
.config on the tool bar and rename the
libreoffice folder to something like
Libreoffice1.
Now reinstall libreoffice and a new
registrymodifications.xcu file will be created, resetting all defaults in the process.