Hi @344876,
I see that you are visiting as a new member to the AutoCAD for Mac forum. Welcome to the Autodesk Community!
I am sorry that you are having problems with your older files In AutoCAD 2017. Have you tried making copy of the files and placing them directly on your hard drive? (No External drive or flashdrive).
If so, try putting a couple files from another application in the same folder. Do those open and save properly?
Can you attach a couple sample files for me to try on my Mac to see if I too have any issue with the older file version?
Please select the Accept as Solution button if my post solves your issue or answers your question.
John Vellek
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