Event id 5 MSExchange Control Panel

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For me, this error occurred after update to CU11.
I can not open OWA after update, but ECP was works good.

This was occurring because the computer object was added to a group that is denying this key/token ms-Exch-EPI-Token-Serialization
As Microsoft said, the following group have the token denied by default.
Domain Admins
Schema Admins
Enterprise Admins
Organization Management

If you run gpresult /scope computer /r and check the groups that the computer object was added.
To fix the problem, you need to remove the computer object from that groups.

Reference
https://support.microsoft.com/en-us/help/2898571/error-message-in-ems-eac-ecp-owa-or-outlook-on-the-web-in-exchange-ser