I'm posting this here since there's currently no thread for 4.3.20
4.3.18 works well for me, but 4.3.20 displays the error message "unable to load r3 module".
I'm including logs from both 4.3.18 and 4.3.20.
Host: Windows XP, Comodo HIPS/Firewall, modified uxtheme.dll, modified shell32.dll.