Running Bless to place boot files failed
I was running High Sierra 10.3.3.
I have a mac pro early 2009, 5,1, 2-2.26 quad core. 14 Gigs ram.
I have my operating system on a partitioned 1 TB SSD.
All had been well until I couldn't start up from the SSD.
When I tried to change back to ssd to be my startup disc I get this message.
"Running Bless to place boot files failed."
Do I have to install my Os again on this drive?
Thanks.
Mac Pro, macOS High Sierra (10.13.2)