Tickets were originally supposed to go on sale late last month, but sales were delayed as organisers said they were working to "refine logistical plans."
Behind the scenes, trouble began brewing between the organisers and their chief investor about six weeks ago, according to the lawsuit. It says Dentsu started to slow-walk payments and accused Woodstock 50 of violating their agreement — allegations that the lawsuit denies without detailing.
Then, on April 29, Dentsu announced it was cancelling the event.
"We don't believe the production of the festival can be executed as an event worthy of the Woodstock brand name while also ensuring the health and safety of the artists, partners and attendees," the company said in a statement at the time. "As difficult as it is, we believe this is the most prudent decision for all parties involved."
Hours later, Woodstock 50 co-founder Michael Lang and Woodstock LLC said the concert remained a go.
"The bottom line is, there is going to be a Woodstock 50th Anniversary Festival, as there must be, and it's going to be a blast," they said.
But the back-and-forth has fueled doubts with just over 100 days to go, and upheaval has continued. Production company Superfly dropped out May 1; organisers say they're lining up a replacement.
Woodstock 50's lawsuit argues Dentsu can't unilaterally cancel the show, noting that their agreement says that "any decision to cancel the festival shall be jointly made in writing."
The suit also accuses Dentsu of telling performers to stay away from the festival and having "pillaged" $17.8 million from festival accounts. Dentsu has said it just "recovered" cash it had put in.
The original Woodstock concert in 1969 was held about 115 miles (185 km) southeast of Watkins Glen on a farm in Bethel, New York.
It's now run by The Bethel Woods Center for the Arts, which has its own anniversary concert planned Aug. 16-18 with performances by Ringo Starr, Fogerty and Santana.