I'm adding a new column to my Filter (e.g. FileType),
but when I restart LR, that new column doesn't persist, and is just disappeared.
I.e. I'm back again with the default 4 columns.
What am I doing wrong?
After adding a column to the Library filters Save it as custom preset and give it a name anything you like.
So, if in case whenever the filters gets changed to default column, you can always select it from your custom preset list.
Let us know if that helps.
Many thanks dude!