(Notes: Exact fixes vary by build and product flavor — AutoCAD-based verticals share many fixes but some fixes may be specific to AutoCAD vs. AutoCAD LT or specialized toolsets.)
After downloading, right-click the .exe file → → Digital Signatures . You should see a valid signature from Autodesk. If this tab is missing or shows "Invalid," delete the file immediately and re-download. Autocad 2018.0.2 Update 64-bit Download
This usually means you either have the 32-bit version of AutoCAD installed or you have already applied a later update (like 2018.1.2) which already includes these fixes. (Notes: Exact fixes vary by build and product