Good morning Kirk
PM should save an arrangement file each time you:
1) Are in Arrangement sort mode and you drag and drop an item or more than one item in a new position.
2) Are in any sort mode and have the preference set to allow arrangements when not in Arrangement sort mode, and you drag and drop an item or more than one item in a new position.
3) Any time you use the View->Make Arrangement command.
I have a single folder with 128 small jpg files in a collection. I tried all 3 of the above options but no .pmarrangement.dat files were created. When I dragged the folder into a PM+ window rather than opening the collection and manually changed the order the .pmarrangement.dat file was created as expected.
When I change the arrangement in a window showing a collection no .pmarrangement.dat file is created but the arrangement is retained when I next open that collection. It seems that when working with a single folder the .pmarrangement.dat file is created but when the arrangement in a collection is changed PM+ uses some other way to retain the order.
Mostly when I make arrangements I do so from a collection containing files from multiple folders but in that case or in the case where a collection is from a single folder changing the arrangement loses the previously stored arrangement. Without there being a .pmarrangement.dat file to copy is there any equivalent way to retain that stored sort order as I try others?
For clarification - I might be making a slide show using files from multiple folders and be trying different sort orders. I'd like to be able make an order, retain it, then experiment with other sort orders and to be able to revert to a previous order.
David