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mvz00 avatar image
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mvz00 asked EXCHAdmin-6515 answered

Exchange Registry Key Missing (Outlook 2016)

Hi,

I have come across and issue with Exchange Hybrid where the Outlook client prompts for credentials after migration. The fix detailed in the article below resolves the issue.

https://docs.microsoft.com/en-us/outlook/troubleshoot/authentication/outlook-prompt-password-modern-authentication-enabled

However, a lot of the Outlook clients seem to be missing the HKCU\Software\Microsoft\Exchange key all together and I cannot work out why some have it and others do not. There is nothing on the internet explaining why this issue occurs. Has anyone come across this before?

Thanks,

Mike.

office-exchange-server-administrationoffice-outlook-itprooffice-exchange-hybrid-itpro
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YukiSun-MSFT avatar image
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YukiSun-MSFT answered YukiSun-MSFT commented

Hi Mike,

However, a lot of the Outlook clients seem to be missing the HKCU\Software\Microsoft\Exchange key all together and I cannot work out why some have it and others do not.

I've tried to search around but cannot find a good explanation for this as well. Based on my experience, it's not uncommon that some registry keys are not existent on clients side and we need to manually add the key when need to apply certain settings. But honestly this doesn't explain why this key is only missing on some clients in your environment.

Given this, would you please have a look at the path below on one of the affected clients and see if the "Exchange" key is located there?
HKEY_CURRENT_USER\Software\Policies\Microsoft

If it's not there either, I'd suggest just going ahead to manually add the registry keys required.


Update:

Current status:
Manually creating the registry doesn't work. Recreating Outlook profiles works, but there are a large number of users in the org.

Suggestion:
Recreate Outlook profile for all users via GPO. For detailed steps, you can refer to the link below:
How to create a new Outlook profile for all users in the domain
(Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)


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Hi YukiSun,

Thanks for the response, however adding the keys manually does not work. I did try this and when the keys are added manually the issue persists and user is prompted for credentials.

Also the Exchange key does not exist under the HKEY_CURRENT_USER\Software\Policies\Microsoft location as suggested.

Thanks,

Michael.

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Hi Michael,

Are the users all located in the same environment?
Have you tried creating a new Outlook profile for one of the users in question and check the results?

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Hi YukiSan,

Yes all users are in the same environment on the same version of Exchange. A re-profile does fix the issue but this is not a feasible solution for a large environment, which is why I would like to find a solution to the problem.

Michael.

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Besides, let's say User A is working fine with the proper registry entries, User B is prompted for credentials and lack of the Exchange key, please have a go using the steps below and see if it can help:
Important: Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.
1. Find the Exchange registry entry on User A's machine, right click on it and choose Export to export the Exchange entry into a .reg file:
31851-1.png
2. Copy the .reg file to User B's machine, double click to import it and check the result.



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Thanks for the response, however doing this for an environment of up to 10,000 staff means that all of these people will need to re-download email and have to manually add delegate mailboxes to the profile (no auto-mapping enabled). This is a huge task to undertake. My preference would be to understand why the problem has occurred and resolve it instead of re-creating profiles in bulk.

Any other suggestions would be much appreciated.

Mike.

0 Votes 0 ·

Hi Mike,
Okay, that's fully understandable. As this issue only occurs to part of the users, we may then try to find out if there's any difference between them that makes the Exchange registry only available to a partial of the users. As mentioned earlier, would you please check the build number of the Outlook clients via File > Office Account > About Outlook and see if all users are running the same version?

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EXCHAdmin-6515 avatar image
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EXCHAdmin-6515 answered

Did the OP ever find the answer to this? I am having the same issue.

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