RE: Autocad Drawings is not valid created by MX Road V8i SS2

Thank you for your response.

I have tested .dwg file provided by you on my system and yes I could see error " Drawing file is not valid".
I would suggest you or can you please confirm to us that the drawing file you are trying to open was not created in a newer version of AutoCAD, with a newer file format than the version you are currently using. For example, a drawing created in AutoCAD 2015 will not open in AutoCAD 2012. Refer to AutoCAD drawing file formats for specific details on the file formats supported by various AutoCAD releases. If this turns out to be the issue, request that the drawing be saved to a version that is compatible with the AutoCAD you are using.

Please confirm the AutoCAD version where you have created or saved .dwg file.

Regards,
Purva Lakde