When performing bulk actions via the Manage Applications screen, you may encounter an error like the one below:
Unable to perform bulk action. Duplicate users detected. Please try searching again.
This will happen if another manage applications page has been opened at any time since the original page was opened.
For example, you're screening candidates for role X, when you get a call from a hiring manager wanting to talk about job Z.
You open up job Z to review applicants, reject some, move some to phone screen etc;, you then go back to job X to complete the screening, to which you would like to bulk move candidates. This will now not work as you have already opened up another manage applications page (job Z) during the time you were initially reviewing the role.
Recruiters are often reviewing multiple jobs simultaneously that could result in several tabs being opened, including multiple 'manage application' tabs.