Invalid username or password, please try again later

ivan.csaba 106 Reputation points
2021-05-12T07:26:07.517+00:00

Hi,

We have a problem that we can’t log in to OWA and the mobile app a few times a day, but the error always goes away after a few minutes. We have Exchange 2019 CU7 and Windows Server 2019 servers.
You receive the following error message:
Invalid username or password, please try again later

During this time, the installed outlook works fine.
The error started about 1 month ago.
My question would be, where could the error be? In which log should we search?
(IIS log, AD log,? Log)

Exchange | Exchange Server | Management
Exchange | Exchange Server | Management

The administration and maintenance of Microsoft Exchange Server to ensure secure, reliable, and efficient email and collaboration services across an organization.


Answer accepted by question author
ivan.csaba 106 Reputation points
2021-05-19T12:35:04.197+00:00

Thanks for your answer.
i installed cu9 a few days ago and the error has not occurred since.

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  1. Ceyhun KIRMIZITAS 0 Reputation points Microsoft External Staff
    2026-09-21T21:21:01.8733333+00:00

    For this type of intermittent OWA authentication issue, I would check the IIS and Exchange HTTP Proxy logs together and correlate them by timestamp.

    Main locations:

    • IIS: C:\inetpub\logs\LogFiles\W3SVC1
    • Exchange HTTP Proxy OWA: %ExchangeInstallPath%\Logging\HttpProxy\Owa

    For the failed request, check the HTTP status, substatus, username, client IP and request URL.

    The LogoffReason=NoCookiesGetOrE14AuthPost entry alone does not show the root cause. The thread also shows that the same entry can appear when OWA is working normally.

    I documented how I correlate IIS and Exchange HTTP Proxy logs for OWA authentication troubleshooting here: https://ceyhunkirmizitas.net/exchange-owa-authentication-troubleshooting-iis-logs-part-4/

    In this case, the problem stopped after upgrading from CU7 to CU9, so I would also make sure Exchange is on a current supported build.

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  2. ivan.csaba 106 Reputation points
    2021-05-20T05:12:16.313+00:00

    Thank you for your help!

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  3. ivan.csaba 106 Reputation points
    2021-05-13T20:13:14.73+00:00

    Thanks for your prompt answer, but unfortunatelly it doesnt work.

    But I found a lof of interesting event, error in IIS log at the time of the problem.

    2021-05-05 05:51:34 IPAddress POST /owa/auth.owa &ClientId=4809F2416145409F88FA9010AB24C203&CorrelationID=<empty>;&cafeReqId=84939961-e9a3-4fae-a083-f8eec0db2b16;&LogoffReason=NoCookiesGetOrE14AuthPost&encoding=; 80 username@keyman UserIPaddress Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64;+rv:88.0)+Gecko/20100101+Firefox/88.0 https://exchange.domain/owa/auth/logon.aspx?replaceCurrent=1&reason=2&url=https%3a%2f%2fexchange.domain%2fowa%2f 302 0 0 38
    2021-05-05 05:51:34 IPAddress GET /owa/auth/logon.aspx url=https%3a%2f%2fexchange.domain%2fowa%2f&reason=2&ClientId=4809F2416145409F88FA9010AB24C203&CorrelationID=<empty>;&cafeReqId=1cf460bb-884d-4201-b7db-47463eb4d6bd;&encoding=; 80 - UserIPaddress Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64;+rv:88.0)+Gecko/20100101+Firefox/88.0 https://exchange.domain/owa/auth/logon.aspx?replaceCurrent=1&reason=2&url=https%3a%2f%2fexchange.domain%2fowa%2f 200 0 0 4

    how should this message be interpreted?

    How can i fix this problem?
    LogoffReason=NoCookiesGetOrE14AuthPost&encoding

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  4. Yuki Sun-MSFT 41,456 Reputation points Moderator
    2021-05-13T05:39:11.51+00:00

    Hi @ivan.csaba ,

    Is this issue affecting all users in your organization?
    Any changes were made in the environment right before the error started around 1 month ago?

    Based on my experience, please run the following command to check the authentication settings for OWA and Exchange ActiveSync:

    Get-OwaVirtualDirectory -Server <ServerName> | fl *auth*  
    Get-ActiveSyncVirtualDirectory -Server <ServerName> | fl *auth*  
    

    Below is the output returned in my Exchange 2019 test lab, you may compare it with your result and see they look the same:
    96231-1.jpg

    With the above confirmed, it's suggested to try resetting FormsAuthentication for OWA virtual directory and restarting IIS to check the result:

    Get-OWAVirtualDirectory | Set-OWAVirtualDirectory -FormsAuthentication $False -BasicAuthentication $True  
    Get-OWAVirtualDirectory | Set-OWAVirtualDirectory -FormsAuthentication $True -BasicAuthentication $True  
    

    Followed by IISreset and also to recycle the app pools for OWA and ECP in IIS.
    Reference: Invalid username and password accessing OWA and ECP

    In case the above doesn't work, I'd recommend have a look at the Event Viewer on the Exchange server for any relevant events. Furthermore, you can go through the IIS logs which by default located at %SystemDrive%\inetpub\logs\LogFiles and see if any clues can be found.


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