Microsoft Defender update causes scans to crash

A bad security intelligence update causes Microsoft Defender to crash during Full and Quick Scans on some PCs. Upgrading to Security Intelligence Update v1.457.236.0 resolves the issue.
Research Snipers

Windows Defender: Microsoft screws up update, disables virus scanners

Microsoft actually wanted to close a security gap, but a current update now apparently partially paralyzes Windows Defender.
The Windows Club

Windows Defender crashing when I open Protection History; Can’t Delete detections.log

Windows Defender is the default antivirus on Windows PCs, protecting them against threats such as malware, viruses, and more. While Windows Defender keeps track of all its actions to safeguard your PC ...
Windows Latest

Windows 11 is warning “Virus protection is off,” Microsoft confirms it’s false, but verify if Defender is actually enabled

If Windows 11 is sending alerts that you need to turn on virus protection and your PC is unprotected, don't worry.