Ottawa Bluesfest has announced one of its headliners has had to cancel because of illness.

Neil Young and Crazy Horse were to be the headline act on July 11 at the Ottawa festival, but the group has cancelled upcoming tour dates.

“When a couple of us got sick after Detroit’s Pine Knob, we had to stop. We are still not fully recovered, so sadly our great tour will have a big unplanned break,” the group said on its website Wednesday. “We know many of you made travel plans and we apologize for the inconvenience.”

Bluesfest said on social media that The Offspring will now headline the RBC Stage with supporting acts Silverstein and Cancer Bats.

“All ticket purchasers holding a single day ticket for July 11 or Pick 3 pass including July 11 will receive further details as soon as possible. Please watch your email for further information!” Bluesfest said.

Single-day ticketholders for July 11 are eligible for a refund.

“If you hold a single-day ticket for July 11 (including GA, VIP, Platinum, Parking Pass, and Coors Light Party Central) you are eligible for a refund if you choose. Any other ticket types in your order are not eligible for a refund,” an email to ticketholders said.

“Note that ticket exchanges, upgrades, or partial refunds for your July 11th day tickets are unavailable. If no action is taken by July 2nd at 11:59 p.m., your July 11th single-day ticket(s) will remain valid, and will not be considered for a refund past this date.”

The link to receive the refund was included in the email that was sent out Wednesday evening.

Bluesfest is celebrating its 30th year. Other headliners this year include Nickelback, Maroon 5, 50 Cent, Mötley Crüe, Mother Mother, Zac Brown Band, Tyler Childers, and Nas. This year, the festival added an extra day for acts Jelly Roll and Shaboozey.

The festival will run from July 4 to 14.