Try a different browser (for example, if you are using Safari, try Google Chrome).
Try logging into another UP resource, such as PilotsUP or Moodle. This may help to determine if the problem is with your UP username/password, or with access to library databases.
Try to access a different database, to determine if the problem is only with 1 resource or access to any resource.
Links to library resources many need an off-campus access prefix to be added to the URL in order for the link to work from both on- and off-campus. Add this prefix using the Off-Campus Link Generator (below).