When viewing a PDF in Blackboard it prompts for a login and then only loads the first page
This is a known issue with Chrome and Blackboard. Blackboard does not intent to fix this issue as it is an issue with Chrome.
For more information from Blackboard: https://blackboard.secure.force.com/publickbarticleview?id=kA31O0000015AIM
Use another web browser to access the PDFs or download the file to view