I encountered the error message "MSXML ActiveX control failed to load" in 64bit IE9 accessing D2 4.5. msxml6_x64 is installed but does not appear in the program list. CTX ActiveX control failed to load also.
While in D2-Config using 32bit IE9 I encountered "Impossible to decrypt the method server response" when importing HR configurations.
All my JDK and JRE are 64bit.