I think my non-DBA background got me on this one today. I renamed my Primary box this morning after doing my SQL 2016 installation last night. Tidied up issues in the Pre-req check for SCCM installation, so I kicked it off and came back to this:
error

Within the ConfigMgrSetup log, I found:

[code]ERROR: SQL server’s Name ‘[WIN-1NOPPABSENJ]’ in sys.servers...