(imported comment written by BenKus)
Hi RP,
I believe this error means that another application is still running and holding a lock on the folder: “C:\Program Files\BigFix Enterprise\BES Client__BESData\actionsite__download” (notice it is a slightly different folder from the one you posted)… This might happen if you have a long-running process that is still active from another action. See if you can look at this folder and see if there is a file there or if you can delete that folder.
Ben