Azure MFA NPS extension stopped working due to expired certification

 Users complained they were unable to log in VMware Horizon Client portal and the logon stuck at "Authenticating...." screen.

So I started troubleshooting the MFA by looking into the NPS event logs and found the log of 6274 with the error message, "The request was discarded by a third-party extension DLL file." 

In AuthZ ? AuthZAdminCh event log category, the Errorcode of "CLIENT_CERT_INSTALL_ERROR" indicated the certificate issue so I suspected the certificate has expired.

Indeed the certificate has expired yesterday....

So I reran the .\AzureMfaNpsExtnConfigSetup.ps1 script in C:\Program Files\Microsoft\AzureMfa\Config on NPS server. It generated a new certificate with another 2 years of period.

Once the certificate is in place, the 2FA login is happy now.

Solution: The size of the extent is less than the minimum in VMware

 I ran out the C drive space in a Windows 10 virtual machine in VMware. However, after adding additional free disk space, the "Extend" option is grayed out in the Disk Management console. Then I tried to use diskpart command and received the error of "The size of the extent is less than the minimum."

Solution: The "Recovery" partition is the problem preventing disk extending, and need to be deleted.

1. Select the Recovery partition, in my case is #3

2. Use the override parameter, "Del partition override"

3. After the Recovery partition is deleted, select the C drive partition and extend again. It should work