Windows Latest reports a recent update for Microsoft's Windows Defender is causing the anti-virus tool to fail scans after a couple of minutes. The bug occurs on Windows 10 systems with Windows Defender version 4.18.2003:
Update for Windows Defender broke the antivirus scans on Windows 10, with the antivirus protection software reporting error “Items Skipped During Scan”. For many users, Windows Defender scans are failing after a couple of minutes, confirming that “scan was skipped” and no threats were discovered on the device.
It’s not clear what items were skipped during the scan by Windows Defender and we also don’t know if Microsoft’s antivirus software is able to detect any threats on Windows 10.
The site also notes that offline scanning seems to work without issues.