HAO LI  8.3.8 adds relaxed check for checking only domainnames.

8.3.9 has GUI to turn the check off.  
(Version 8.3.9)

HAO LI  Just check the link with Saft 8.3.8 and on crash. Have you nightly built WebKit installed?  
(Version 8.3.8)

HAO LI  If you mean nightly-built WebKit, it does not work now since there are too many differences to the default WebKit that comes with the OS.  
(Version 8.3.4)

HAO LI  Oh, I see, I do have some repeatable download problems verified by users, and they are all related to the access from China. We all know about the Great Firewall, my guess is that it can have some connections to that. Anyway, you can always ask me to send the file via email if you can provide your account info in email and a reason why you cannot download.  
(Version 8.3.1)

HAO LI  Saft is a plugin/patch and cannot live its own life but inside Safari. Auto-download cannot be done - maybe with an external helper app. But it's really not that hard to download if you have Autofill on in Safari - it's just two clicks away from the download.  
(Version 8.3.1)

HAO LI  You have "Block Plugin" or animation on under Safari menu -> Block Images and Plugins.  
(Version 8.3.1)