On November 12, MAMAMOO appeared as guests on MBC FM4U radio program 'Kim Shin Young's Noon Song of Hope'. However, due to sudden muscle pains, member Whee In was unable to attend. 

On this day, the MAMAMOO members updated fans on Whee In's whereabouts, after DJ Kim Shin Young shared with viewers, "Whee In was not able to join us today because of neck pain." Solar added on, "She hurt her neck during dance practice. It's bound to happen. These hard choreographies get to you." 

According to reports, Whee In visited the hospital this morning (November 12) due to muscle pains in her neck, potentially a herniated spinal disc. The group's agency will continue to update fans on her condition.