can't download offline address book after migrating from exchange2013 to exchange online

hello Joey Dong and thank you for your help.

i sent you the results of Get-OfflineAddressBook

and the results of the Test-Email Autoconfiguration

also note that when i try to insert the oab address into chrome it asks me for username and password but i can never login.

when i try with Edge i get the error HTTP ERROR 401

Hi Barbarbarero,

Good day to you. We noticed that your case have Hybrid environment, hence we escalated your case. I am an escalation engineer and I am writing this thread now. It is my pleasure.

Since the issue occurs after migrated the mailbox, please first run command Get-OfflineAddressBook to check if you can get the OAB. 

Furthermore, please determine whether the Autodiscover service is working, and check access to the Offline Address Book. Check whether Outlook and the computer can access the Offline Address Book file on the server:

1. Start Outlook.
2. Hold down the CTRL key, right-click the Outlook icon in the notification area on the right side of the taskbar, and then click Test E-mail AutoConfiguration.
3. Click to clear the Use Guessmart check box, and then click to clear the Secure Guessmart Authenticationcheck box.
4. Click to select the Use AutoDiscover check box.
5. Type the email address and password, and then click Test.
6. On the Results tab, note the path of OAB URL.
7. Click the XML tab, locate the <OAUrl> and </OABUrl> tags, and then copy the path that's displayed between the tags. Paste the path into the address box in Windows Internet Explorer, add /OAB.xml to the end of the path, and then press Enter.

Then, please also copy the full test result from XML and paste them in Word and share with us. We'd like to check the test result. To protect your privacy, we'll collect the result in Private Message.

Looking forward to your update and we'll always be here for you.

Regards,

Joey
'

this is a screenshot of SARA diagnosis

Hello @shyamal Debnath ...

we used hybrid full migration during the hybrid migration wizard ... the migration is completed for some users .... we still have a lot of users to migrate... 

i have office365 outlook client installed ... but the problem happens with all clients ... other users have outlook 2016 and outlook 2019 ... all users that are fully migrated have this problem ... i already tried SaRa but it didn't solve ... i'll try it again .. we also tried removing cached mode ... i also tried deleting the cached offline address book from the appdata/local/microsoft/outlook

Hi Barbarbarero,

Thanks for the screenshot. May I know which migration method have you done (e.g. cutover migration/hybrid) to migrating in Exchange Online? Is it migration completed or still on process? 

Does this issue happen with every migrated users or specific user?

Which Outlook 365 desktop client version are user using please provide us with the detailed screenshot about this, see About Office: What version of Office am I using?

Please use the Office 365 Support and Recovery Assistant (SaRA) tool that can diagnose the Outlook problems and create new Outlook profile to check this issue. See: About the Microsoft Support and Recovery Assistant

Moreover, please provide us with detailed email domain via the Private Message for further analysis.

Your patience and cooperation are highly appreciated. Have a nice day and stay safe!

Best regards, 

Shyamal