If a bead breaks on the weft of beaded weft extensions, the best course of action would be to remove the entire weft and have it re-beaded by a professional. Continuing to wear the extensions with a broken bead can cause the hair to become tangled and damaged, and may also cause the beads on the rest of the weft to fall off. Additionally, missing a bead can lead to the weft unraveling or the beads sliding off the weft. It is always best to have a professional handle any issues with hair extensions to ensure that they are properly fixed and to avoid causing further damage to your hair.