The challenge I most often face in my workplace in the area of communication is that many people don't communicate enough and don't place the same value on communicating thoroughly. Sometimes it's a lack of identifying stakeholders and finding out what kinds of communication they prefer (or not even thinking of stakeholders and that they would benefit from or be impacted by things that should be communicated to them).
Sometimes it's a lack of skill, and sometimes it is a control issue (we won't communicate information to people because if they don't have it we have control).