Jess Glynne has become the second act in a week to pull out of the TRNSMT music festival in Glasgow for health reasons.
The singer said she had been ordered to rest her voice completely for the next 10 days because of vocal cord damage.
Glynne cancelled a performance at the Isle of Wight festival two weeks ago, blaming anxiety.
Her withdrawal from TRNSMT comes days after Snow Patrol announced they were pulling out of their Sunday night slot.
A statement from the Northern Irish band said guitar player Johnny McDaid required immediate surgery on a neck issue.
Scottish singer Lewis Capaldi will step in as a special guest to fill their slot.
Glynne released a statement saying her decision to pull out of TRNSMT "absolutely kills me".
She said she had been diagnosed with a vocal cord haemorrhage and would have to cancel all her shows up to 14 July.
The singer said her doctor warned that if she wanted to keep performing, she needed to "urgently take a break".
She added: "Basically he told me I have been completely overdoing everything.
"In the last six months I've performed almost 100 shows, I've pushed through at times when I know I've been tired and overstretched and I got to breaking point, my voice literally got to breaking point.
"The thing is, I am my voice. If my voice goes, I go. I am so privileged to do what I do, I am so privileged to have fans out there who come and see me. But I never want to be less than 100%."