Can you check what permission are set on that folder and what types files are present inside folder .
Do EICAR test and see that scanner are working fine .
Generate MER and raise support case so that we can look into the issue in more depth.
MAC O/S Error: Unknown error received from scanners
I have the same error. I have a 2016 MBP 15" at 10.12.6.
Is there a fix for this problem? It looks like this problem goes back to 2013.
The newer posts are not in this forum.
Can you check what permissions are set on that folder and what types files are present inside the folder?
What happens if you perform an EICAR test?