A move command is in fact two commands together.
First it will copy the files from source to target folder. After the successful completion of copy files, it will delete the source files.
You have to find out where you are getting the problem, during copying or during the delete after copy.
Instead of moving the files, try to copy the files first. After successful copying you can delete them later.
Check the ownership permissions of the target folder. If the ownership permissions are with another user like System, take ownership and after copying the files, revert the permissions back to the default owner.