2.1.1.47356 64bit beta installer doesn't recognize Design

Thanks for the report. This will get fixed in the next installer.

Do you know how to manually add the Krakatoa plugin to Max? If not you add these entries to the [Directories] section of \Autodesk\3ds Max 201X\plugin.ini (or \Autodesk\3ds Max 2013\en-US\plugin.ini):

Krakatoa=C:\Program Files\Thinkbox\Krakatoa\3dsMax201X
ThinkboxSchematicControl=C:\Program Files\Thinkbox\ThinkboxSchematicControl\3dsMax201X

NOTE: Replace 201X with the appropriate version.