HELP Needed please >>> Users suddenly cannot connect to Microsoft OneDrive and Sharepoint

[kites182]

Hello to all,

Need some advice on how to fix this issue.

Our users suddenly cannot connect to Microsoft OneDrive and Sharepoint.

Here is the error. (attached the screenshot)

Thanks,

Kites

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[Johan_Witters]

Hi Kites,

have you checked the certificate the browser complains about? Probably you get the default (self-signed) certificate presented by the Fortigate because of eithter SSL inspection or application control trying to decrypt the traffic. You can try to solve this by disabling inspection, or by installing the Fortigate certificates on the clients so they are trusted.

You might want to check these:

https://docs.fortinet.com...cate-into-web-browsers

https://pub.kb.fortinet.com/ksmcontent/Fortinet-Public/current/FortiOSNotebook/fortios_certificate_m...

Good Luck,

Johan

[tanr]

Since this occurred with just certificate inspection, you really should check the logs to see what was actually happening. 

It may be that the FortiGate was correctly giving an error for an invalid certificate on OneDrive or SharePoint servers, and its notification of this (with self-signed certificate) was what caused the result you saw.  But without analyzing the logs you won't know.

[tanr]

Think I found what is probably causing this.

Fortiguard just changed OneDrive/SharePoint to the "File Sharing" category, and lots of people are seeing stuff blocked because of this.

See Per https://www.reddit.com/r/fortinet/comments/f2k95t/did_fortiguard_update_sharepoint_category_to_file/ for discussion.

[tanr]

Looks like they reverted it, as https://fortiguard.com/webfilter?q=Sharepoint.com&version=8 now shows a category of information technology.

[kites182]

Thanks for all your inputs!

As per checking today, all Certificate Inspection Profiles are now working properly with all of my IPV4 policies.

I haven't done anything.

Seems like problem was with Fortiguard as posted by tanr on this threaad.

Thanks again!

Kites

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[kites182]

Forti500D wrote:

did you enable deep inspection ???

Thanks. I will check it out.

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Kites

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[kites182]

Thanks. I will check out the link you gave. =) 

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Kites

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