I have the exact same issue. Also, it seems to recognise my Civil 3D 2011 English United Kingdom as a US version. Managed t o install on 2012 Eng UK 64bit, but I get a fatal exception when trying to import any PKT file created with SAC. A closer look at the installer indicates that the 2012 installation encouters a FE too.
Tried this on two workstations with the same results.