https://community.cisco.com/t5/network-platform-api/unable-to-reserve-dnaclab/m-p/5338436#M8529 <P>Hi,</P> <P>Whenever I try to reserve a lab from the site "<A href="https://developer.cisco.com/catalyst-center/&quot;" target="_blank">https://developer.cisco.com/catalyst-center/"</A>&nbsp;for the options "Reservable Sandbox" or "Always-on Sandbox", it is throwing the below errors.</P> <CENTER> <H1>400 Bad Request</H1> </CENTER><CENTER>Request Header Or Cookie Too Large</CENTER><HR /><CENTER>nginx</CENTER> <P>&nbsp;</P> <P>How shall I proceed further?</P> Tue, 14 Oct 2025 14:26:11 GMT Anand G 2025-10-14T14:26:11Z https://community.cisco.com/t5/network-platform-api/unable-to-reserve-dnaclab/m-p/5338436#M8529 <P>Hi,</P> <P>Whenever I try to reserve a lab from the site "<A href="https://developer.cisco.com/catalyst-center/&quot;" target="_blank">https://developer.cisco.com/catalyst-center/"</A>&nbsp;for the options "Reservable Sandbox" or "Always-on Sandbox", it is throwing the below errors.</P> <CENTER> <H1>400 Bad Request</H1> </CENTER><CENTER>Request Header Or Cookie Too Large</CENTER><HR /><CENTER>nginx</CENTER> <P>&nbsp;</P> <P>How shall I proceed further?</P> Tue, 14 Oct 2025 14:26:11 GMT https://community.cisco.com/t5/network-platform-api/unable-to-reserve-dnaclab/m-p/5338436#M8529 Anand G 2025-10-14T14:26:11Z https://community.cisco.com/t5/network-platform-api/unable-to-reserve-dnaclab/m-p/5338441#M8530 <P><a href="https://community.cisco.com/t5/user/viewprofilepage/user-id/294167">@Anand G</a>&nbsp;open the sandbox page in a private or incognito browser, this will redirect you to the main sandbox catalog page - this works ok.</P> Tue, 14 Oct 2025 14:42:19 GMT https://community.cisco.com/t5/network-platform-api/unable-to-reserve-dnaclab/m-p/5338441#M8530 bigevilbeard 2025-10-14T14:42:19Z