IIS 8.5 runtime error


I'm new to IIS technology and need your detailed explanation and help please.

I have two servers have IIS 8.5 installed and using DNS round robin solution.  servers are 2012 servers.

my set up  for DNS A record and round robin is as below. All I did was created 2 A records pointing my site name with below IPs..  ( Hope not missing anything else. This is only for internal users)

 server1 IP =10.x.x.1   10.x.x.2 to use for the site  ( this is additional IP on the server)
 server2 Ip =10.x.x.3   10.x.x.4  to use for this site  ( this is additional IP on the server)

IIs is configured with its defaults except authentication settings. (Anonymous is disabled and windows authentication is enabled)
Did not made any change to physical directory for permissions? (inetpub folder)
not all the users but 2 out of 1 user is receiving attached error. Can you please tell me where to look for more information and also what to do by step by step please? Thanks for your help.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Attachment? 2 out of 1, is consistent? The same user with the error ALWAYS gets the error, even after trying multiple times? Or you mean the same user has the problem about 50% of the time?
kuzumAuthor Commented:
sorry attached the error,  yes, the same user gets the error. I just noticed that any user receiving ping response from site link that is hitting  server2 is having the attached error. seems issue is more around server2?
kuzumAuthor Commented:
checked the differences between both servers and noticed that on the server2(which I believe problematic one)

from site properties>edit permission>security   I cannot see authenticated users groups?? do you think this is compulsory to have on both servers?
Both should be on the same domain, and have permissions matching.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft IIS Web Server

From novice to tech pro — start learning today.