Sometimes when deleting the contents of my SandBoxes I receive this error:

Is it normal to get this kind of error? What am I doing to receive this error? Is there a way to prevent it? Could it be that the processes for the Boxes have not been terminated?

If it matters; I run a batch file which executes a three shortcuts which are targeted to delete the contents of the three of my SandBoxes. This may not be the best way so I ask if there are any alternatives. I know there's an option to automatically delete contents after each session but that's not what I want for particular SandBoxes

Each "delete sandbox" command has two phases. Phase 1 renames the sandbox folder from "SandBox2" to the funny name you see "__Delete_SandBox2_.......". Phase 2 deletes all the folders with the funny names.

What happens is that by running delete sandbox multiple times, you get multiple "phase 2" jobs running at the same time, all trying to delete the folders with the funny names, and conflicting with each other. Eventually one of these "phase 2" jobs tries to delete a folder that some other "phase 2" job already deleted. Thus you get the error.

In the next version, a "phase 2" job only deletes the folders that belong to a particular sandbox, so you will not get this problem anymore.