We're sorry you have experienced this Blackboard issue that occurs only on Blackboard Windows servers.
Make sure you apply patchset 3 and then the LRNSI-9453 patch. See details in the article below:
Article #000024594 - Cumulative Patch 3 for Blackboard Learn, 9.1, Service Pack 10
After the above patches have been applied, clear your cache for your Internet browser (Internet Options/Browsing History/Delete).
Please let us know if you have any issues after doing the above.