That's a permissions issue with your computer - not with TurboTax. But I don't know how to deal with that on a MAC. @macuser_22 flagging you on this.

1)Be sure that the CD is NOT in the CD drive.

2) Restart the Mac.

3) Try saving to your own Desktop.

I am not using a CD - downloaded program directly from Intuit. Thanks however. 

Will this help?  Mac can not save files

https://ttlc.intuit.com/community/saving/help/turbotax-for-mac-cannot-save-tax-files/00/25533

Thanks I did as you suggested but I get the same error message

Exactly how are you saving the file?

Are you using the Top menu bar -> File (hold the Option key) and Save As?

Do you get the pop-up box that asks for a password or save without a password (choose without a password) ?

Exactly what is the error message?