Comment 1 for bug 23684

As of release 5.05, this has been fixed.
https://www.jwz.org/xscreensaver/changelog.html

The Debian bug linked above isn't about this specific bug but that
the message isn't obvious enough.
It isn't displayed with big flashing red letters but it's there.

This text appears in the message box if you fail to enter correct
password with Caps Lock on:
"Authentication failed (Caps Lock?)"