More problems for ex-Oakland Raiders center Barret Robbins -- the troubled 42-year-old was arrested outside of a bar in Boca Raton, Florida after allegedly getting violent with several people.
TMZ Sports has learned ... Robbins was taken into custody around 12:30 AM on Tuesday -- after witnesses say he attacked a person inside of a bar, struck another person outside the bar ... and then roughed up a mother and her daughter after that.
One witness says after the incident, Robbins sat down at the scene and waited for cops to arrive.
He was eventually arrested on 2 counts of felony battery.