Crashing if I want to open a dwg file

Hello,

I was looking for an autocad replacement to view en make small adjustments to drawings I have or get send.
My files are all dwg and I'm using it on a Windows computer but every time I try to open a dwg file the program crashes. Does anyone know how to fix this?

thanks

I seem to be able to open dwg files.  Although these weren't created with the most recent version of AutoCad.

What version of AutoCad were these dwg files created with?