While reviewing the Dissolvable Agent Server (DAS) logs or scan results, you may see ffcopy errors regarding files not found or zero byte files.
Retrieving service artifact (directory item): \\10.x.x.x\ADMIN$\FFCDIR\feb0e83b-76A5-4625-BBC1-EFF6F83AD90C of size 0 bytes code: 0]]
This is caused when the file expected to be present no longer exists. When the DAS goes to collect the data, it doesn't exist if there were no results.
It is not expected that all files can be accessed, and still exists after the initial detection of its presence. It is expected to see these errors.