In revision 1741, when the ini was last changed it says:

; JA2 1.13 - Unfinished Business (JA2 1.13)
; VFS_CONFIG_INI = vfs_config.JA2113.ini

While I think it should be:

; JA2 1.13 - Unfinished Business (JA2 1.13)
; VFS_CONFIG_INI = vfs_config.UB113.ini

While we're at it, why not just change it so there is some consistent naming scheme in these files, i.e. something like this:

; JA2 1.13
VFS_CONFIG_INI = vfs_config.JA2113.ini

; JA2 1.13 - Vanilla (JA2 Classic)
; VFS_CONFIG_INI = vfs_config.JA2Vanilla.ini

; JA2UB 1.13
; VFS_CONFIG_INI = vfs_config.UB113.ini

; JA2UB 1.13 - Vanilla (JA2UB Classic)
; VFS_CONFIG_INI = vfs_config.UBVanilla.ini

There's still some inconsistency in the naming of the ini files themselves (omission of the "113" in Vanilla inis and omission of "JA2" in UB inis, but well.