NimbostratusHi randyrue,
If you have more than one iRule on a VIP dealing with HTTP::respond it is important to manage the execution using various commands. If the HTTP::respond fires then there are a limited amount of "HTTP" commands that you can use, otherwise you will recieve a TCL error. One of the methods of guarding against that is to check the HTTP::has_responded command in your code: https://clouddocs.f5.com/api/irules/HTTP__has_responded.html
You could check your LTM logs for messages like this:
01220001:3: TCL error: /Common/<iRule_name> <HTTP_REQUEST> - ERR_NOT_SUPPORTED (line 1)     invoked from within "HTTP::host"
A good breakdown of the issue and solutions is here: https://support.f5.com/csp/article/K23237429
In a nutshell, adding the code "if { [HTTP::has_responded] } { return };" to the beginning of your iRules after the when HTTP_REQUEST command should help.
Best,
Josh
