Error when logging in to "Outlook on the web" via HENNGE Secure Browser for Android

for Microsoft 365


We have confirmed that the following error occurs when accessing to Outlook on the web via HENNGE Secure Browser for Android from July 19, 2021.
Error Message:
500 Something went wrong.
Repeating redirects detected.


As a result of our investigation, our system team has confirmed that the issue is most likely caused by Microsoft's changes in reading cookies when accessing to Outlook on the web.

When a user accesses to Outlook on the web, Microsoft sets a cookie in the browser and If the cookie does not exist in the browser next time the user log in, the 500 error will be returned.

Since HENNGE Secure Browser does not allow cookies to be saved by default due to the concept of the service, it has been affected by the changes and is displaying the 500 error message.

A workaround for this issue at this time is to allow cookies to be saved as described below.


We will continue to investigate this issue with High priority, including the possibility of fixing HENNGE Secure Browser.

We apologize for any inconvenience this may cause and we would appreciate it if you could consider the above workaround.


・Go to HENNGE Access Control Admin Console > "Browser Policy Groups" section and edit a target Browser Policy Group. Then select the "Allow" option  in the "Save Cookie" section and save the setting.


・If you have registered the URL of Outlook on the Web as the "Start URL" or "Bookmark" in your Browser Policy, change the URL to the following format.<>
   i.e.) In case your domain is "", the URL should be as below.


change the URL to the Microsoft 365 portal instead of the Outlook URL.<>
  i.e.) In case your domain is "", the URL should be as below.
※If you use the above URL, you will need to tap the Outlook icon to access to Outlook on the Web via Microsoft 365 portal.


・After changing the Browser Policy, users also have to enable the "Save Cookie" setting on their HENNGE Secure Browser apps.
※To apply this change, users must need to restart HENNGE Secure Browser.


※No need to try this workaround if users do not see any errors on HENNGE Secure Browser.
1. Access to Outlook on the web
2. In case the error message is displayed, go to the "Settings" and select "Clear Cookie".
3. Close the setting menu, and then users will be asked to log in again.

We have confirmed some cases where users are able to access to Outlook using the above workaround.


・After the preparation, cookies will be saved in HENNGE Secure Browser. Therefore when users launch HENNGE Secure Browser, they will not be asked to log in and the page you opened last time will be displayed.

・If the session is disconnected as time passes, users may be signed out from Microsoft 365. In that case, please clear your cookies and log in again.



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