Hi flyingeddies,
Do you mean the .dwg file type is not listed in the Save As Type list?
Is this a recently happened issue?
How about other file types like .dxf?

Please try repairing Visio via Control Panel to see if the issue can be fixed.
Any updates, please feel free to post back.
Best regards,
Yuki Sun
Please remember to mark the replies as answers if they helped.
If you have feedback for TechNet Subscriber Support, contact
tnmff@microsoft.com.