Install Office 2016 is blocked

[Hans_van_Deursen]

Hi All,

Being new at the forum I would like to ask a question.

We want to install Office 2016 from te the portal at portal.office365.com. This used to work, but since our webfiltering is turned back on again the installation is being cut off.  We have tried to disabled Webfiltering, and then it works fine.

Now we want to look at log files about where the blocking is being done. But neither the URL nor the IP address is in the logging. 

Does any of you recognize this and has a possible solution?

Regards, Hans 

[netmin]

Hi and welcome to the forums (sometimes we're slow ... ),

as far as I know, MS has been adding more security features (like HSTS) to some of their Office servers. In case you are utilizing the full SSL inspection functionality, it might indicate that the Office installer now does a sort of HPKP (HTTP public key pinning) and doesn't like the MITM certificate provided by the Fortigate. If so, try exempting the MSOffice domains from webfilter inspection - or - switch to certificate-inspection only for applicable domains.

[nicoco59]

Hello,

We have the same issue here... Did you find a workaround ? 

We don't use full ssl inspection.

Thank you.

Nick

[boneyard]

you also don't see the logs? is the policy set to log?

[hmtay_FTNT]

In addition to netmin's answer, if your Web Filter is set to "Proxy" mode instead of "Flow", you have to keep your FortiOS version up-to-date. If you are using FortiOS 5.2, try to get it upgraded to the latest 5.2.xx and same if you are using 5.4. The proxy module update requires an update to the FortiOS, unlike the Application Control or IPS modules which are handled by the IPS Engine and updates to the IPS Engine are easily pushed together with the regular signature database update. A lot of bug fixes on the proxy modules are usually included in the new FortiOS version changelogs.