Toll Free: +1 888 900 4529
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Toll Free: +44 800 088 5522 
Toll Free: +1 888 900 4529
| Toll Free: +44 800 088 5522 In November 2013, Cumulative Update 3 was released for Exchange Server 2013. This update resolved many issues with Exchange Server and proved to be advantageous for both Administrator and clients. However, the users can encounter various issues with the Cumulative Updates.
With Cumulative or some other updates, the users can come across some difficulties after the installation. Some of the issues include:
In case of Cumulative update 3 and above version, the basic functionalities that get hindered are:
On installing Cumulative Update with Exchange Server 2013 and above versions either in DAG or non DAG mode, access to OWA or ECP is denied but it is found that Outlook is working effectively.
If case of such scenarios either of the following errors will be generated:
However, both the above mentioned errors can prevail in Exchange Server environment but we will focus on “ECP And OWA Logins Fail With Error 500 in Exchange 2013” . Let’s now move to the reason due to which this error occurs.
The main reason behind the log in failure of OWA and ECP is the mismatch of canary tokens between the client and server
A canary is usually a secret token between client and Server in OWA, ECP or some other web services that is stored in the cookie collection of the browser and gets submitted with various requests which the browser sends. For each request the value of GUID stored in the URL is compared with the one stored in session state. If the value of GUID stored in these location do not match or if the value of GUID is lost from the URL, the request becomes malicious and it is blocked. As a result of it, the users will encounter “http error message 500: Internal Server Error” and the Server will come across an unexpected condition that stops it from executing the request.
As mentioned above that the mismatch of canary tokens between the client and the Server is responsible for the generation of error 500. Let’s have a practical look on the functionality of Canary tokens in normal state and at the time of error generation.
What Actually Happen
What Happens When The Error Is Encountered
If you encounter ECP and OWA logins fail with the error 500 in Exchange 2013 then there is no need to lose your nerves. You can tackle this scenario by following these steps:
NOTE: It is advised to take backup before preceding these steps
CN=Client Access,CN=“Organization name”,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=“domain”
NOTE: Check the subfolders too, as the canary values can be stored to them.
NOTE: At the time of recycle the established session will be lost but it is not an issue to be worried about.
Conclusion
With the Cumulative Update 3, Exchange Server 2013 – OWA and ECP logins fail with 500 error. The basic cause of this error is mismatch of canary tokens between the client and the server. It is a tough condition in which the users lose control from OWA and ECP. However, one can tackle this situation manually by following the above mentioned steps.
