The Design Environment tab of the Database properties dialog allows the selection of two items related to compatibility modes for running 4D v3.x.x (v1.5.x of server) databases under 4D v6.0/6.5.

"Use V3.x.x Startup Method Scheme"
The Use V3.x.x Startup Method Scheme property allows you to let the STARTUP method be called automatically on startup, as in earlier releases of 4th Dimension. The Database methods (new in version 6) are active only if this property is not selected. If you are converting an old database and want to use the new Database methods architecture, you can copy your STARTUP procedure into the On Startup database method and deselect this property. For more information about database methods, see "Database Methods" on page 483 of the 4D 6.5 Design Reference Manual.

"Use V3.x.x File Procedure Scheme"
If this property is selected, Table methods (triggers) run according to the rules established for File procedures in earlier releases of 4th Dimension. File procedures were executed for input layouts only. They executed before the Layout procedure was executed for every input layout. File procedures were also executed whenever anything in the input layout was used (e.g., a button was pressed or data was entered in a field). This property can be used for either converted databases or databases created with the current release of 4th Dimension. For information on the new trigger architecture, see the section: "Triggers" on page 481 of the 4D 6.5 Design Reference.