iSCSI disconnects after KB4525243 installation.

Message: c:\windows\system32\iscsicpl.exe The stub received bad data.

iSCSI to fiber enabled storage is disconnected and iSCSI initiator tries to connect.

VMs are off-Critical as they are stored on the external storage.

Even after restart, the iSCSI initiator can’t connect.

Storage seems to work, but Hyper-V cannot connect to it and mount the drive needed.

Services starting and stopping:

-IP helper

-iSCSI initiator

-Themes and a few more.

Check latest updates installed:

• KB4525243
• KB4524445

Removed the KB4525243 and rebooted server.

Crashed the profile, because the Event Notification Service could not start.

Services keep start and stop:

-IP helper

-iSCSI initiator

-Themes and a few more.

Entered with the local administrator account

Started services -> Sign out -> Sign in with the Domain Administrator account. Profile is still in an erroneous state. Services stopping unexpectedly.

Initiated Restore of System State from last night’s backup. Note that currently the KB4525243 is removed.

After system restore finished and many restarts took place, the KB4525243 is installed and iSCSI can start with no problem.

Remounted the problematic iSCSI from the storage, only after power cycling the storage.

Remounted using the exact same configuration as in the installation, featuring MPIO and CHAP authentication.

Everything works fine.

Potential causes: We installed the Bitlocker feature while a restart was pending after the KB4525243 installation.

The KB4525243, as described on here, refers to Security updates to Microsoft Scripting Engine, Internet Explorer, Microsoft Graphics Component, Windows Input and Composition, Windows Cryptography, Windows Virtualization, Windows Kernel, Windows Datacenter Networking, and the Microsoft JET Database Engine.

We will examine further.