PAPA ROACH was forced to cancel its appearance last night (Tuesday, August 21) at the Grand Rapids, Michigan stop of the Rockstar Energy Uproar Festival tour due to singer Jacoby Shaddix's ongoing vocal issues.Christian hard rockers P.O.D., who have been headlining the second stage during the Uproar trek, revealed the news in a tweet, explaining that they were asked to step up to the main stage yesterday to make up for PAPA ROACH's absence. They wrote, "Headed to Grand Rapids. Papa Roach dropped off today's show so we're covering their slot last minute. Prayers 4 Jacoby to heal his vocals." PAPA ROACH has yet to comment on the Grand Rapids concert cancelation or offer an update on Shaddix's condition. Shaddix admitted in a recent interview that he has been suffering from throat problems. Speaking backstage at a show in Allentown, Pennsylvania, Shaddix said, "I went to a vocal specialist. I have what's called a node that's forming on my vocal cord, so it's like a callus on my vocal cord, and so it's fucking with my top range of my vocals for the last week, so I've actually been pretty bummed out." He added, "I took some steroids, and that'll help the swelling and hopefully that'll help it go away. But if it doesn't get better, it's one of those things where you have to get surgery and do the whole thing." Shaddix was hopeful that the problem would be better in time for the band's stint on the Uproar Festival tour, which kicked off on August 17 in Bonner Springs, Kansas. "I think I'll be all right," he told Loudwire earlier this month. "I've got a speech and vocal therapist at the current time to learn how to sing through this and work through this and take care of myself. Really, it's just a matter of having a little bit more discipline than I'm used to, you know, as far as vocal rest and warm-ups and cool-downs and all that kind of stuff." The Uproar Festival also features SHINEDOWN, STAIND, REDLIGHT KING, ADELITAS WAY and others. The vocal scare is the latest in a series of struggles for Shaddix, who has also dealt with marital strife and recurring addiction issues in the past year or so. He told The Pulse Of Radio that all his problems found their way into the new PAPA ROACH album. "I was a mess. I'm a mess," he said. "You know, I was in the process of getting sober again and I just, you know, I'm a wreck. I'm a rock 'n' roll freight train. I'm a VH1 story. It came through on the record, you know, so there's desperation, there's hope, exhilaration, there's empowerment...it's a myriad of emotions. You know, there's songs on this record that I listen to and I'm just — they hit so deep to me, I'm like, 'God, I don't even want to listen to that song right now.'" The band's new studio set, "The Connection", is due out on October 2. First single "Still Swingin'" arrived late last month. A kinetic typography lyric video for "Still Swingin'" can be seen below.