All FoxPro and Access database dbf files should be saved in "<account_dir>\data" folder.
This folder has all the needed permissions and is especially created by SD for this purpose.
FoxPro uses "NETWORK SERVICE" local user, so it needs both read and write permissions for "NETWORK SERVICE" user in folder "<account_dir>\www\" while there is only read permission for this user.
You should copy all the DB files to folder "<account_dir>\data"
Using the VDS GUI, modify the FoxPro DSN to point to a new path and run the script again.