After upgrade when accessing the Citrix Gateway the page is stuck at spinning wheel.

To resolve the issue perform following checks.

1) Launch the Gateway page and open Developer tools (Browser) to cross check all URI's are loading with 200 Status Response.

 

If for a URI example style.css , tmindex.html(when using AAA Based authentication),index.html (when only Citrix Gateway with basic authentication) ,string.en.js we receive 404 Error , this would point to issue with Portal Theme  . Try creating a New Theme or Change to Default Theme.

2) The Gateway Page is redirected to https://test/logon/LogonPoint/tmindex.html  and developer teams show 200 Status for all requests .Follow the below the steps.
 a)Check the AAA Virtual Server used for Authentication .
 b)If any Login Schema is bound with customization switch to default Login Schema and Test .
 c)If the page loads successfully we can create a new Login Schema as a clone of old one using the reference documentation .
https://docs.citrix.com/en-us/citrix-adc/current-release/aaa-tm/authentication-methods/multi-factor-nfactor-authentication/nfactor-authentication-configuring.html

3)Save configuration

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Problem Cause

1) In case of Citrix Gateway the Custom Portal Theme  Files get corrupted during the course of upgrade.
2) In second condition of using AAA the issue happens due to Login Schema getting corrupted after upgrade,