a fly in the ointment
• a minor irritation that spoils the success or enjoyment of something.
Similar:
snag,
hitch,
catch,
drawback,
difficulty,
problem,
weakness,
defect,
pitfall,
complication,
obstacle,
hurdle,
barrier,
stumbling block,
bar,
hindrance,
impediment,
handicap,
disadvantage,
restriction,
limitation,
disbenefit,
hiccup,
facer,
spanner in the works,
monkey wrench in the works,
