Showing results for 
Show  only  | Search instead for 
Did you mean: 

This product reached the end of support date on March 31, 2021.

HTTP Error 401 - Unauthorized: Access is denied due to invalid credentials, while trying to access CAS



We are trying to set up Health Check monitoring tools for our CAS servers. The team responsible for setting this up states that when they are trying to access the CAS they get HTTP 401 error.

They generally use a script to automate the accessing.

But, we can also see this error appear if we use Fiddler while trying to access CAS server.

We would like to know the reason why this error comes up and how can we eliminate this?

Is their a work around for this?





Well pobably you are using credentials that doens't work - right?

Have you tried using others?

We are not using any kind of credentials. We are simply accessing the CAS, in a web browser and we see the error appear in the fiddler.

OK - but after the initial failure, do you actually GET IN to the CAS?

Is there something in the GUI saying anything or is it just in Fiddler you find the errors?

Its just the fiddler which shows the error. We are able to get into the CAS.

I believe there is a initial check on the CAS, which checks if the user was already logged in few mins back. I say this because, when I logged into CAS and simply closed the IE window. And, went back to CAS, I did not had to go through the login process again, was already logged in.

This time I did not see any error in Fiddler too.

Dynatrace Pro
Dynatrace Pro

This is normal behaviour.

If you browse to http://cas/ you'll get a 401 and redirected to the logon page where you can then logon.

If you want to use scripts to log on to the CAS, the proper way to do so is generate a UID string to pass as part of the calling URL.

See UID GENERATE (Commands console)

you then add the string it creates to your URL.


htt p://cas/LSServlet?lsEntryName=Citrix+dashboard&dmiAction=Generate


h ttp://localhost/LSServlet?lsEntryName=Citrix+dashboard&dmiAction=Generate&UID=uidstring

you can then get CAS results without having to authenticate manually.