January 8, 2018—KB4056895 (Monthly Rollup)

Symptom

Workaround

When calling CoInitializeSecurity, the call fails if passing RPC_C_IMP_LEVEL_NONE under certain conditions.

When calling CoInitializeSecurity, the call may fail when passing RPC_C_AUTHN_LEVEL_NONE as the authentication level. The error message that's returned on the failure is: STATUS_BAD_IMPERSONATION_LEVEL.

This issue is resolved in KB4057401.

Microsoft has reports of some customers on a small subset of older AMD processors getting into an unbootable state after installing this KB.
 
To prevent this issue, Microsoft will temporarily pause Windows OS updates to devices with impacted AMD processors at this time.

This issue is resolved in KB4073576.

Because of an issue that affects some versions of antivirus software, this fix applies only to computers on which the antivirus ISV updated the ALLOW REGKEY.

This issue is resolved in KB4093114. You no longer need the following ALLOW REGKEY to detect and be offered this update: 

HKEY_LOCAL_MACHINE"Subkey="SOFTWARE\Microsoft\Windows\CurrentVersion\QualityCompat\cadca5fe-87d3-4b96-b7fb-a231484277cc

After installing this update, some systems running both PIC and APIC interrupt controllers may experience system crashes.

This issue is resolved in KB4077561.

Editing some group policies using GPMC or AGPM 4.0 may fail with error "The data present in the reparse point buffer is invalid. (Exception from HRESULT: 0x80071128)" after installing this update on a domain controller.

This issue is resolved in KB4074594.