Morgan Wallen canceled his Sunday concert in Mississippi just a few minutes before showtime, leaving thousands of disappointed fans in his wake.

The country star was set to perform on April 23 at Vaught-Hemingway Stadium in Oxford, as part of his “One Night at a Time World Tour” with opening acts Hardy, Ernest and Bailey Zimmerman. Wallen, 29, had played at the 64,000-seat stadium on Saturday, April 22, and Sunday’s concert was planned as the culmination of a two-night stint.

But Wallen never took the stage on Sunday. As fans waited for him to appear — after the opening acts had performed — a message was posted on video screens at the stadium, informing the audience the show was canceled because the headliner had lost his voice.

Wallen’s fans are known to be devoted, sticking with him through various controversies. However, some folks in the crowd immediately took to social media on Sunday, expressing their anger and disappointment. (NOTE: Some of the social media posts below contain vulgar language.)

The country star issued an apology via Instagram on Sunday night, saying “my voice is shot” and “I promise you guys I tried everything I could.”

Here’s the full text of Wallen’s message on social media:

“After last night’s show I started losing my voice so I spent the day resting up, talking to my doctor and working through my vocal exercises trying to get better. I really thought I’d be able to take the stage and it kills me to deliver this so close to showtime, but my voice is shot and I am unable to sing. All tickets will be refunded at point of purchase. I am so sorry, I promise you guys I tried everything I could.”

According to Setlist.fm, Wallen performed a full show on Saturday night in Oxford, singing more than 25 songs. Fans also posted photos of Wallen mingling with admirers on Saturday afternoon at an Ole Miss baseball game at Oxford-University Stadium/Swayze Field.

Wallen prompted fan chatter earlier in the week when he stumbled and fell on stage during a concert at the KFC Yum! Center in Louisville, Kentucky. The star recovered quickly from the tumble on April 20, however, and kept on singing.

Wallen, 29, is touring on “One Thing at a Time,” a new double album that’s held the No. 1 spot on the Billboard 200 album chart for six weeks in a row.

READ MORE:

Morgan Wallen falls on stage in Kentucky, makes ‘Yikes!’ face for fans

Morgan Wallen: 6 things to know about the polarizing country superstar

Morgan Wallen miffed, boots fan who threw drink at him during show in Australia