4D does not support a Case-Sensitive file system, it is not designed for this type of partition.

In older versions of 4D, the application would just fail and crash randomly if ran on a Case-Sensitive file system.

In newer versions of 4D, an error dialog is presented when running from a case-sensitive file system letting the user know they must run it on a case-insensitive file system.

If the computer being used for 4D is using a Case-Sensitive file system then the drive will need to be reformatted to be case-insensitive.