I have been successfully deleting and recreating caches for several days now. Until today. Error says it's in use somewhere. Where?! Does anyone have any insight? ArcMap 10.2.1 with ArcGIS for Server 10.3.
Try stopping your ArcGIS Server service (local services) and then deleting the cache folder. This should remove all locks before the delete.
And such a quick answer, I'm impressed!
Have a good one.
...and if at some point that doesn't unlock it totally, make sure to close all ArcMap and ArcCatalog (and sometime windows file explorer), even if not accessing the folder. I find that occasionally that locked persist, especially in Catalog, even if I select a different folder. Just a trouble shooting tip for future is the restart solution doesn't work.
Retrieving data ...