Did a clean install of F37 and the following error was generated just after the software was installed.
Did a standard install on ext4 with a couple of partitions:
Did the same with F36 and it works fine! Could well be a bug!
This seems a common issue with F37 and some Imac devices
Time for this iMac to go to the big orchard in the sky!
Install F38 Beta. It should be fixed there.