file detected unable to scan

hi, my mac should be clean, i even formatted. but avast after complete scan still detect 6 files unable to scan.
should i be worry?
what can i do to fix it?

http://Schermata 2017-03-26 alle 16.45.40

Files avast can not scan is not a detection, just a scan error message and is normal
The message should also tell you why

How do I handle files that Avast can’t scan? >> https://blog.avast.com/2014/02/28/how-do-i-handle-files-that-avast-cant-scan/

I spent some time looking into this problem in the Windows forum before saying I was on a Mac. Apparently the Windows version of Avast lists why files are unable to be scanned. This information does not seem to be available in the Mac version. One reason that was given over there was that the files were password protected, I don’t know if this is the same on a Mac.