Andrew J. Price | Technical Blog

Office Servers and Services MVP | Founder of UC and Cloud Day | Founder of Microsoft Cloud User Group

Office Online Server – Error Microsoft Office 2016 requires Universal CRT (KB2999226)

Hello Readers

When deploying Office Online Server today, I ran into a error when trying to install the media via the mighty Pat Richard script and running the setup executable manually.

Setup is unable to proceed due to the following error(s):
– The installation of a Microsoft Office Online Server Language Pack requires that Microsoft Office Online Server be installed.
– Microsoft Office 2016 requires the Universal CRT (KB2999226) which failed to install.
Correct the issue(s) listed above and re-run setup.


The KB referenced above has two dependancies which will need to be checked or addressed before install KB299226

Install this KB2919442 first – http://www.microsoft.com/en-gb/download/details.aspx?id=42162

Install this KB2919355 second – https://www.microsoft.com/en-us/download/details.aspx?id=42335

Please be aware this KB will take a long period of time to install as its nearly 700mb. You maybe prompted to restart the server after install, please restart then continue to proceed.


Install KB299226 https://www.microsoft.com/en-us/download/details.aspx?id=42335

This completes all the required steps for Office Online Server KB prerequisites and you will now be able to install your OOS Farm successfully.

Andrew J. Price

2 thoughts on “Office Online Server – Error Microsoft Office 2016 requires Universal CRT (KB2999226)

  1. Hi – Thanks for sharing above info.

    Would you mind sharing the entire install process of Office Online Server including external certificate process?



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