On-Premises Script Error - "The Primary File...model database"

Issue

Error message:
"The primary file must be at least X MB to accommodate a copy of the model database"

Root Cause

When the database is created it uses the model DB as a template, the model DB is a built-in system database in SQL.

When the On-premises database is created with the creation script, the following SQL statement sets the database size to 50 MB.

DECLARE @dbDataFileSize VARCHAR(10) = 50

Resolution

Open SQL Server Management Studio, right-click the model DB, go to Properties -> Files and check the initial size (MB)

Edit the SQL script that the On-Premises wizard created, line 30, and change the value from 50, in this example, you see that the initial size is 128MB, so change it to 129MB, and that will resolve the problem.