If you have an older database that was created with a version of 4th Dimension prior to version 6.0 and want to convert it to version 6.7, the easiest way is to open and convert it with 4th Dimension v6.0.6r8 first. For this purpose, the demonstration mode of 4D is adequate; that is, you don't need a serial number just to open and convert an existing database. You can download various versions of 4D applications from:

https://www.4D.com/downloads/aciprod.html