If you take the skill "Ranged shadow impact" you are no longer able to combo/chain cast shadow missile. After taking this skill each and every cast of shadow missile causes your character to stop for a few seconds before being able to start a new attack chain and you are never able to chain cast shadow missile again. It is pretty game breaking and a real pain in the ass because you can not get "Storm" with out this skill. So much for basic QA bug testing when a skill tree this simple doesn't even get tested.

Hello @horngoat
We just released a new patch on PC supposed to fix this issue. It will be released on PS4 and Xbox One quite soon as well!
Sorry for the inconvenience and thank you for your feedback