According to https://www.dogparksoftware.com/MacLoggerDX Help/mldxfc_faq.html you need to: How come Look Up doesn't work ? Make sure you have the Call Book popup set to QRZ XML (or the Call Book of your choice), your account is up to date and your Username and Password are correctly set. If that's not clear or working, I'd suggest reaching out to the developer of MacLoggerDX.
