Would you be able to send a photo of the plant? Are the limp branches brown or dry? Did this happen quickly such as overnight? My best guess is frost damage or lack of water. Feel the soil and add water if the top inch is dry to the touch. If a cold night caused the damage you can snip off the damaged tips later this spring after your weather is free of frost. Don't worry too much as Viburnums are pretty tough shrubs and I have a hunch your shrub will survive. Keep growing, Marianne Binetti