Why is my student unable to open/upload/submit an assignment?
First, you should always make sure that any desired content for the student to view is set to Available. For more on how to do this, see our post on Using the Assignment Tool.
Also, using a web browser that is not certified for Blackboard may cause problems for students attempting to open a test/assignment, submit a test/assignment, or use the file upload feature. See Supported Browsers Tutorial for a list of web browsers currently supported by Blackboard.