By default libre office checks (in that order):

• checks paperconf result
• checks envs: LC_ALL, LC_PAPER, LANG
• defaults to en-US and ''letter'

Solution to set A4:

apt install libpaper-utils

/etc/papersize

a4

or

echo "a4" > /etc/papersize

In general UI integration is missing, ie. libreoffice-kde ,libreoffice-gtk or libreoffice-gnome. Also icon set is needeed, i.e. libreoffice-style-tango

# Debian Jessie:
sudo apt-get install libreoffice-gtk3 gtk2-engines-oxygen libreoffice-style-oxygen
 
# Debian Buster
sudo apt-get install libreoffice-gtk3 libreoffice-style-tango

java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException
	at net.loomchild.segment.srx.io.Srx2SaxParser.<init>(Srx2SaxParser.java:173)
	at org.languagetool.tokenizers.SrxTools.createSrxDocument(SrxTools.java:51)
	at org.languagetool.tokenizers.SRXSentenceTokenizer.<init>(SRXSentenceTokenizer.java:53)
	at org.languagetool.tokenizers.SimpleSentenceTokenizer.<init>(SimpleSentenceTokenizer.java:37)
	at org.languagetool.Language.<clinit>(Language.java:60)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:315)
	at org.languagetool.Languages.createLanguageObjects(Languages.java:111)
	at org.languagetool.Languages.getAllLanguages(Languages.java:97)
	at org.languagetool.Languages.<clinit>(Languages.java:39)
	at org.languagetool.openoffice.Main.getLocales(Main.java:547)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.JAXBException
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:588)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
	... 11 more
java.lang.NoClassDefFoundError: Could not initialize class org.languagetool.Languages
	at org.languagetool.openoffice.Main.getLocales(Main.java:547)

Open libreoffice calc, go to

• Tools menu
• Extension Manager
• find LanguageTool. Open source language checker 3.2 extension and update it

• cooder
• Code Colorizer http://extensions.openoffice.org/en/project/code-colorizer