While trying to update the IT Management Suite (ITMS) 8.0 to HF6 the Symantec Installation Manager (SIM) will complete the file download and installation. However, as SIM is configuring the install it will hang trying to restart the Symantec App pool.
"The World Wide Web Publishing Service (W3SVC) remains in a "stopping" state, but cannot fully stop or it cannot be restarted." (Source: KB4338815)
IT Management Suite 8.0.
Symantec Installation Manager 8.1
Windows Server 2012 R2
The problem was introduced by Microsoft KB4338815 from July 10, 2018.
The fix is to install Microsoft KB4338831 from July 18, 2018.