Perform clean installation by following the steps below: 

1. Uninstall DesginCAD.

2. Remove it's related folders (DesignCAD) from

  a. Documents

  b. C:\ProgramData\IMSIDesign

  c. C:\Program Files\IMSIDesign (Program Files(x86) if it's a 32-bit version)

3. Setup FIles from C:\Program Files (x86)

4. Install DesignCAD.