The latest update to Internet Explorer (version 11) may prevent the 'compose message' edit window from opening. To make sure you are able to compose messages when working in Blackboard with Internet Explorer 11, you must set your browser to ‘Compatibility View’:
Open Internet Explorer 11.
Press the Alt key to display the Menu bar (or right–click the Address bar and then select Menu bar).
Click Tools, and then click Compatibility View settings.
Type in ‘mccneb.edu’ to the ‘add this website’ bar and click Add.
Close the dialog box.
In Blackboard return to the course homepage, then go to compose a mail message or discussion post. The edit window should load normally.