Generator functions do not have total browser support yet. IE11 does not support them. Node 6 is actually the first Node version with total support for them:<p><a href="https:&#x2F;&#x2F;kangax.github.io&#x2F;compat-table&#x2F;es6&#x2F;" rel="nofollow">https:&#x2F;&#x2F;kangax.github.io&#x2F;compat-table&#x2F;es6&#x2F;</a>