Goodmorning, I have just did a clean USB installation of Mac OS 10.13 GM on my SSD in APFS, it seems that is working quite fine apart the fact that I can't see my 2 internal HDD formatted in HFS+ (I also have the backup in one of those).
when Mac OS boot up it tells me that 3 drives are illegible and need to be formatted (like when you connect a wrong partitioned drive in the past).
Even in Disk utility I can't see them.
In system report I can see the two HDs... (I have attached a screenshot below)
EDIT: clover r4207 installed on the EFI of the main SSD and did a clean configuration apart from my DSDT.aml installed in the right folder
My system is the first one in the rig, tell me if you need something else for troubleshooting.
Thank you for your help