Chkdsk running at started after Quick Scan

I’ve has several machines reboot and start running the long version of chkdsk (including free space) after initiating a Quick Scan from the Business Avast dashboard. Has anyone else experienced this issues and how can I resolve it?

This entry is from the event viewer after the Quick scan has completed

The file system structure on the disk is corrupt and unusable. Please run the chkdsk utility on the volume \Device\HarddiskVolumeShadowCopy6.

Could you provide more detail about the issue and your environment? Eg, Windows version, are you getting BSOD, do you have shadow copies enabled, etc.