I get a similar error. When I click on the Upgrade To 4.00.204 button, the release notes come up for a second, then lock up SixBit and the Release Notes. I can CTR ALT DEL, close the release notes and SixBit is functioning again. Have tried that even with a reboot.
I am running SB 4.00.200 on a Win7 laptop.
Thanks,
John