From 12:00 PM on Saturday September 13, 2014 to 7:00 am on Monday September 15, 2014 users who were attempting to add material to courses or post discussion board messages containing web links or HTML content received an error (“The extension target is invalid.”). On Monday morning we discovered morning that there was a problem with Blackboard’s unsafe HTML filters. The filters are applied against any new or modified content to ensure malicious scripts cannot be added. We’ve corrected the problem with these filters. The issue was resolved and users are now able to edit content in courses.