It is well known that when $K$ is a local or global field the Galois cohomology group $H^{3}(K,K_{text{sep}}^{times})=0$ where $K_{text{sep}}$ denotes the separable closure of $K$. Could someone give an example of a field $K$ where $H^{3}(K,K_{text{sep}}^{times}) neq 0$ and why it is non-zero in this case?