Unable to display videos because your session has expired

When I log into stream, I get a notification under the links that says I need to refresh my browser. Refreshing does not fix the problem. If i then click the link to look at video, it tells me "Unable to display videos because your session has expired". I log out and back in, same problem. 

Not sure what to do. Trying to upload my powerpoint videos I have made but I am stuck because of this issue.