Summary:
If your new Blackboard course site was copied from a course that used Lockdown Browser, you will need to access the Respondus Dashboard in the new course in order to re-initialize Lockdown Browser for any existing tests.
If your new Blackboard course site was copied from a course where Respondus Lockdown Browser had been used, you will need to open the Respondus Dashboard at least one time in the new course. A message will appear informing you that the existing exams within the course can now be taken with Lockdown Browser.
The Respondus Dashboard can be accessed from the course menu by navigating under Course Management > Course Tools > Respondus Lockdown Browser.