When using 4D on Mac OS you may run into situations where you need to select a file (e.g. a Data file or Log file) in a file chooser dialog but the file you want to select is grayed-out.
Files on Mac OS have two pieces of meta information that are related to this issue: the TYPE and CREATOR codes, described here:
If the TYPE or CREATOR of a 4D file is incorrect then you may not be able to select the file in a file chooser dialog. This information can be lost when moving a file from Windows to Mac via SMB, for example.
To fix this problem you simply need to alter the TYPE and/or CREATOR code to be of the correct value.
There are many tools for Mac OS that allow you to view and/or edit the TYPE and CREATOR codes for a file. Once you have such a tool the easiest way to get the correct values is to create a file of the desired type on a Mac machine and check the values for that file. For example, if you need the TYPE and CREATOR codes for a 4D data file, create a new database and check the .4DD file in your tool.
As of 4D 2004.5 you can use this reference:
Structure Type: BAS5
Structure Creator: 4D06
Data File Type: DAT5
Data File Creator: 4D06