Bricscad V11 has a syntax problem in the description field of the .deb file. This problem causes a failure during the upgrade to Ubuntu 12.04 but it also makes the installer unusable in clean installations of Ubuntu 12.04. The fix is quite simple and similar to the DraftSight on Ubuntu 12.04 64bit workaround.
You have to edit the control file inside the .deb installer. Here is the complete workaround:
You have to edit the control file inside the .deb installer. Here is the complete workaround: