fly in the ointment

Etymology
A reference to 10:1 in the Bible (King James Version; spelling modernized): “Dead flies cause the ointment of the apothecary to send forth a stinking savour: so doeth a little folly him that is in reputation for wisdom and honour.”

Noun

 * 1)  Something (especially a minor thing) which ruins or spoils everything else, or makes it less pleasant; a nuisance or problem; a disagreeable or unpleasant detail.

Translations

 * Belarusian: лы́жка дзёгцю ў бо́чцы мёду
 * Chinese:
 * Mandarin: ,
 * Czech: vada na kráse
 * Danish: hår i suppen
 * Dutch: haar in de boter
 * French:, , , ,
 * German:
 * Polish: łyżka dziegciu w beczce miodu
 * Russian: ло́жка дёгтя, ло́жка дёгтя в бо́чке мёда
 * Serbo-Croatian:
 * Cyrillic: муха у јухи, мува у супи
 * Roman: muha u juhi, muva u supi
 * Swedish:, malört i glädjebägaren
 * Ukrainian: ло́жка дьо́гтю в бо́чці ме́ду