This is a common problem problem with our internal updating mechanism, Sparkle. A lot of applications use it and experience this problem.
Apparently, this new version of Sparkle adds support for password-protected disk-images. While this is kind of useful, the password dialog is triggered for a small number of users in case the disk-image is not attached in time (aka "if it fails to attach, it must be password protected!" Right..).
Felix Paul Kühne from VideoLAN, Source
- Some user report that empty password field is working.
- Another solution is to make the disk image available at the moment.
Although we are sure that our software is safe, it's not advised to enter your real password from the protected image to any 3d party software, even Show Pro.