I installed MA3 screen saver with the downloadable zip file and extracted its .scr file into c:\windows\system32\ directory/folder. I don't recall having this problem in an older version from over a month ago (don't remember what version it was).
I used display properties to configure the screen saver. I just pick clock and mess around. Easy to reproduce is clicking on the time to change default 10 seconds to something else.
I changed both analog and digital clock times from 10 seconds to 8 seconds and then to 12 seconds, and nothing crashed.
Of course, that doesn't help fix your crashes.
Note: there are about 5 meanings for "installed". I suggest you try using the "Installer Version" from SereneScreen, and then after that putting the Beta in system32.