Without language you are definitely out

Under bizarre circumstances Bosnia and Herzegovina in 2018 will be deprived with one 'man in black' from the UEFA list. Dragan Petrovic is an licensed referee and can lead matches from the European competitions. However, he failed the test by making several mistakes from English language. As no one will replace him, this country will have one official less on the list for the current year.
Together with Admir Sehovic, both had to replace Ognjen Valjic and Edin Jakupovic who retired.