'Apply' is basically a greyed-out option for any of these files - either scan result - nor can you send them to the 'chest'. Is that because these files are harmless of has the Apply application been disabled please?
because they are not detections....but a scan error report. avast just gave you a scan error report and the reason why files that can not be scanned for reason given by avast is just that and does not mean they are infected

files that could not be found error is usually gone if you reboot and scan again

some files could not be scanned is the most frequently asked question in the forum so lots of info if you forum search