CRM 4.0 server access denied 401.5 errors

Posted on 2009-02-12
Last Modified: 2012-05-11
CRM 4.0 server 401.5 errors

We have a test environment that has been running CRM 4 on server 2008 for a couple of months with no problem.

Since a recent restart of the server access to CRM 4 has been denied . when attempting to connect to the web page ftom s client or the sserver  you are prompted for kigin credentials and then it fails with 401.5 error got .5 from the log file

According to
HTTP 401.5: Denied by custom ISAPI/CGI Web application

An ISAPI extension or CGI application denied the request.


Identify which ISAPI extension or CGI application denied the request, and contact the developer or vendor to determine a solution.

All the services are running ,  I have removed and reinstalled the IIS role and this has had no effect. I have given everyone permissions to INETPUB directory . Next step contact developer  ?

How do I find out which account the app is running with to try and rectify it if that is the problem ?

Any help would be appreciated
Question by:EGC
    LVL 15

    Expert Comment

    "Custom" is a red herring imho.

    Was it just a reboot, or were there hotfixes, etc?
    What about CRM rollups performed and no reboot afterwards?

    Are you using a Host Header or something like that?

    What port is CRM on?  If you go to the server and then in IE to http://localhost:5555 (or whatever port) do you still get that error?


    Author Comment

    We are not using a host header, the problem is the same on the server and from the clients. I have done multiple re-boots
    It may well have been an update that caused it I'm going through them now an next step will be to restore from tape.
    Do CRM rollups come down with Windows update or do they need to be installed manually ?

    Author Comment

    Just checked update history , I have applied latest updates thsi week whuilst troubleshooting but prior ti that there had been no patches since October , so it appears that an update did not cause the fault.
    When I try repair the CRM install it fails the system rewuiirements  because it does not have access to the default site also
    LVL 15

    Expert Comment

    CRM Rollups do not come with Windows update.

    So are you saying that you can't get to any of the websites on this server?
    LVL 10

    Expert Comment

    It could be coincidental that this was associated with some new updates.  We had the same problem a number of months ago and wasted days (ugh) trying to remove updates and/or rollback the server - all to no effect.  Finally we realized that a switch had gotten fried which had disabled access to the server.  Shame on us for not looking at the fundamentals first.

    A few things to try:
    * Can you get to the CRM website while you are logged directly onto the server?
    * If yes, can you ping the server from other machines on the network?  Can you get to other sites on the same server as CRM?
    * Can you ping the SQL server from the CRM server?
    * If all else fails, can you restore the server to a previous state to verify that it was the updates that caused the problem? (make sure you back everything else up first)

    Accepted Solution

    Answer was the site was corrupted and not passing authentication on correctly
    So had to reinstall
    I backed up the SQL data files unistalled CRM and reinstalled ensuring I used the same organisation name and it worked.

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