The issue may appear when the customer will use a non-default SQL user. Normal install with the Windows user should not see this issue.
In most scenarios, the standard installation process handles database connectivity automatically. Manual SQL user configuration is considered an advanced setup and is rarely required for standard environments.
Most sites do not need to specify a unique SQL user.
Default Instances: If you are using a standard SQL installation, simply leave the advanced fields blank.
Named Instances: If your SQL instance is non-default, you only need to provide the Instance Name.
When to Use Advanced Configuration
Manual entry is generally only necessary if your database is hosted on a remote server or within a specific domain environment.
Domain Users: If the database is on a domain, we recommend using a Domain User account.
Existing Credentials: If a specific SQL user is required, ensure that the account is already configured and carries the necessary permissions on your SQL Server before starting the installation.
If you select Advanced Configuration during installation , ensure you use the proper syntax to include the domain:
Format:
DomainName\SQL_UsernameExample:DESKTOP-XYZ\sql_admin