While Luxembourgish is official in Luxembourg, it isn't official in the EU. Here's something that I'm blatantly copy-pasting from Wikipedia:
"In September 2010, Luxembourg's foreign minister Jean Asselborn declined a request of the Alternative Democratic Reform Party (ADR) to make Luxembourgish an official language of the European Union citing financial reasons and also that German and French being already official languages would be sufficient for the needs of Luxembourg."
"In September 2010, Luxembourg's foreign minister Jean Asselborn declined a request of the Alternative Democratic Reform Party (ADR) to make Luxembourgish an official language of the European Union citing financial reasons and also that German and French being already official languages would be sufficient for the needs of Luxembourg."
Oh, well.