Some years ago we have removed FelixCAD and the free FelixCAD LT version from our website, because we could not support and maintain this old product anymore. Particularly there are a lot of compatibility issues with Windows Vista, 7, 8 , 8.1 and 10. A re-activation of FelixCAD/FelixCAD 5 LT is also not longer possible.
Our follow-up CAD program is ARES Commander with new user interface, integrated 3D ACIS functionality and enhanced programming interfaces. Detailed information can be found under:
Please test our 30-days-trial version. It supports also FelixCAD and FelixCADT LT drawing file format (.flx) for file conversion.
Further we recommend to change to the modern CAD alternative DraftSight. The CAD-kernel of DraftSight is also developed by the Graebert GmbH: