Unable to create a self signed Certificate for SQL Server 2017(14.x.xxxx)
You need to enclose CertStoreLocation, Subject, DnsName and FriendlyName with double quotes.

There is no need to specify a location as it will default to "Local Computer/Personal/Certificates" where it needs to be in order to use it by SQL Server.

This will generate a valid certificate on Windows Server 2016 that will be usable by SQL Server 2017:

New-SelfSignedCertificate -Subject "CN=insert FQDN here" -DnsName "&lt;insert FQDN here&gt;","insert NetBIOS name here" -FriendlyName "Self Signed Certificate Friendly Name" -KeySpec KeyExchange -KeyLength 2048 -NotAfter (Get-Date).AddYears(5)


Please replace 'insert FQDN here' and 'insert NetBIOS name here' with the actual FQDN and NetBIOS name keeping the double quotes.