From Xojo Documentation
| This item was deprecated in version 2019r2.
Property (As Boolean )
| This property is only available on the macOS platform.
For cross-platform compatibility, use ＃If...＃Endif with the Target... specifiers to make sure you will not attempt to use this property on an incompatible platform.
If True, a Save is needed. Call the Save method to save the changes.