You are unable to drag and drop files from Windows Explorer onto AutoCAD Start screen to open them, or when double-clicking on a DWG file it opens AutoCAD but not the drawing you double-clicked on, or you have a Logitech Mouse with Programmable Buttons and the custom keystrokes applied to the buttons no longer function in AutoCAD
Drag and drop, double-click and the mouse button programming are all part of the Windows functionality, and an update to Windows causes this issue to occur only for AutoCAD-based Products.
The following Windows Registry fix was used to resolve this issue:
1. Press Windows + R button.
2. Type Regedit in the dialog that appears.
This will open Windows Registry Editor.
3. Navigate to: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
4. Find the key EnableLUA, and change 1 to 0.
5. Press OK and restart the computer
Note: It is recommended that you back up the Registry prior to making changes. If necessary, contact your IT department to make these changes.
Here is the information regarding that specific key