This happens only when you work on a dbf table, not with layers. If you have unsaved changes and try to close, a NullPointer exception will be raised, due to an attempt to access the layer in showWarning(), though it doesn't exist. I think we should simply avoid any other checks when layer is null, and continue the same way as if the layer were in edition. I upload a really simple patch which works perfectly for me.
|Resolution||Works For Me|