měi zhōng bù zú
everything is fine except for one small defect (idiom); the fly in the ointment
měi yī gè rén dōu yǒu měi zhōng bù zú de dì fang
However excellent, everyone has his defects.
There is always a fly in the ointment.
cf idiom 美中不足[měi zhōng bù zú], everything is fine except for one small defect