References can't be transferred to RefWorks, because the browser in use has disabled popups.
If the browser has disabled popup windows, references can't be transferred to RefWorks.
If you can't allow all popups for security reasons, you can manually select to allow them just from a certain database. When you transfer a reference from a database for the first time, your browser should ask for a permission to allow popups for just the page you're on at the moment.
Instructions for different browsers are shown below.
RefWorks tab doesn't show in Word
Activate Write-N-Cite in Word with the guide showing below. Word should be restarted for the changes to apply and RefWorks -tab to appear.