Why do I receive an HTTP 500 Internal Server Error from the Citrix Gateway if I take three minutes or longer to complete Duo authentication?
![Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro](https://www.informatiweb-pro.net/images/tutoriels/virtualisation/citrix/netscaler-gateway/13-remote-client-config/7-netscaler-module-citrix-system.jpg)
Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro
![Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro](https://us.informatiweb-pro.net/images/tutoriels/logos/us/citrix-netscaler-gateway-11-0-configuration-and-integration-with-xenapp-xendesktop.jpg)
Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro
![Beim Laden des vDesk-Portals erhalte ich die Meldung "HTTP/1.1 Internal Server Error 43531". – Hochschulrechenzentrum – TU Darmstadt Beim Laden des vDesk-Portals erhalte ich die Meldung "HTTP/1.1 Internal Server Error 43531". – Hochschulrechenzentrum – TU Darmstadt](https://www.hrz.tu-darmstadt.de/media/hrz/vdesk/webseite_wdb___fehlersteckbrief/FAQ_-_vDesk-Portal_-_Fehler_HTTP1.1_Internal_Server_Error_43531_-_Markierung_Keine.png)
Beim Laden des vDesk-Portals erhalte ich die Meldung "HTTP/1.1 Internal Server Error 43531". – Hochschulrechenzentrum – TU Darmstadt
![Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro](https://www.informatiweb-pro.net/images/tutoriels/virtualisation/citrix/netscaler-gateway/13-remote-client-config/2-remote-pc-ca-certificates.jpg)
Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro
![Error "Http/1.1 Internal Server Error 43531" when accessing Citrix Gateway after upgrading to version 13.0 build 71.40 Error "Http/1.1 Internal Server Error 43531" when accessing Citrix Gateway after upgrading to version 13.0 build 71.40](https://support.citrix.com/files/public/support/article/CTX291268/images/0EM4z000002NDKE.jpeg)
Error "Http/1.1 Internal Server Error 43531" when accessing Citrix Gateway after upgrading to version 13.0 build 71.40
![Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro](https://us.informatiweb-pro.net/images/tutoriels/logos/us/thumbs/citrix-xenapp-xendesktop-7-6-single-sign-on-sso.jpg)
Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro
![Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro Installation, configuration and integration of Citrix NetScaler Gateway 11.0 with XenApp/XenDesktop - Citrix - Tutorials - InformatiWeb Pro](https://www.informatiweb-pro.net/images/tutoriels/virtualisation/citrix/netscaler-gateway/12-dmz-config/1-netscaler-virtual-ip-dmz.jpg)