Please take the following steps to resolve this issue:
  1. Reset your Blackbaud Hosting Services profile password.
  2. Log in to the hosted application as a user with rights to Admin>Security.
  3. Go to Admin>Security and open the application profile experiencing the issue.
  4. Uncheck Windows Authentication and mark  Authentication checkbox and create a password.
  5. Save and close the user profile.
  6. Open the user profile again.
  7. Unmark RE7 (or EE or FE if applicable) Authentication and mark the Windows Authentication checkbox
  8. Enter 'BLACKBAUDHOST\[hosting profile username]' (Ex. BLACKBAUDHOST\1234REUser1) in the Login field under Windows Authentication.   (case sensitivity is important when typing the hosting profile username)
  9. Save and close the user.
  10. Exit and sign out of your hosted application and launch the application to verify that Windows Authentication for the affected user is now working.
If this issue is still persisting after performing the above steps Please document and be prepared to provide the below listed information and then Click Chat with Support and reference this article. 
  1. Prepare a set of hosting and application usernames for an affected user.
  2. Please document clear and exact steps to duplicate the issue.