Ravinia 2016 tickets on sale Tuesday

HIGHLAND PARK, Ill. (WLS) -- Music lovers trying to buy tickets for Ravinia's 2016 summer season ran into some problems early Tuesday morning.

The tickets went on sale at 5 a.m. on ravinia.org. But many people complained about issues with credit card processing.

Festival officials tweeted around 5:45 a.m. that it's investigating and thanked customers for their patience.

About an hour later, Ravinia tweeted that everything should be back to normal.

More than 140 concerts are scheduled at the north suburban venue from June 2 to Sept. 11. This year's highlights include Bob Dylan, Patti LaBelle, Diana Ross, Frankie Valli, Duran Duran, Lauryn Hill, Dolly Parton and Tony Bennett. Check out the full calendar at ravinia.org/calendar.