Thanks for your reply Jeremy –
This project currently takes up over 2.5 TB in space.
My goal is to hand the client a slimmed down version for archiving purposes. Media Manager claims this will be 25 GB which sounds about right for a 1 hr show.
The plan is to hand over the new, Managed 25 GB project on a separate drive to the client, while the original bloated version remains intact until the dust settles.
I have a fair amount of storage available, but not 2.5 TB!
AND, since I get this error even when I am simply trying to make an offline version of the project, with no disk specified, I am pretty sure that disk space is not the issue here.
Since I have never had this problem in the past, I am wondering if this is yet another bug in FCP6.