KB4011021 May Fail to Install for Office Online Server

EDIT: 1/18/2018: This update has been replaced by KB4011022.

KB4011021 may fail to install for Office Online Server. This appears to be due to a failure to install the GAC binaries. To prevent a partial installation of this KB, I would suggest holding off on applying this to production systems. The wacserver-x-none_MSPLOG.LOG installation log file will have entries similar to the below.


If you have attempted to install and the installation failed, re-install the November 2017 ISO and subsequently install KB4011020.

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