What AutoCAD LT release? 2015,2016,2017? 

Windows 7, 8, 10? 

You can try the following; 

• Run AutoCAD LT as administrator with full access rights to the user account. 
• Uninstall/ Re-install Microsoft C++
• Uninstall/ Re-install Microsoft .NET
• Uninstall/ Re-install AutoCAD 

Let me know if you have any other questions. 

Sarah Emmsley
Technical Support Specialist