Q.Wisteria suddenly dying
Our 12-year-old wisteria has suddenly started to die from one week to the next. The leaves were all green and within a week the leaves are turning yellow curling up and falling off. This has spread from one or two branches to the entire wisteria. We are at a loss to figure out why.

Curling leaves is generally an indication of pests or disease.
This link will help you address the most common issues.
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-diseases.htm