Hi Yutaka, According to the manual about customization from website, we are trying to customize those builtin messages without recompiling DeleGate by defining: MOUNT="/-/builtin/* http://127.0.0.1:8080/delegate/builtin/* host=-management.xxx.com.au" It's still using the builtin message, rather than our own html page. I tried vURL with /builtin/* or /-/builtin/*, both not working. From website the /-/ means the delegate host, but I do not really understand what it is actually. Our version is 9.1.1. The other mounts are working fine, i.e. MOUNT=/mgmt/* http://127.0.0.1:8080/mgmt/* host=-management.xxx.com.au Looking forward to hearing from you. Best regards, David