IRule and Error Checking

This is caused by something called operator precedence. The "not" operator (an alias for "!") is of higher precendence than starts_with, ends_with or equals. So, what's happening is that the not is being applied to the [HTTP::uri] operand and then the result of that is being checked whether it ends_with "/". Clearly not what you want.

Try adding some parenthesis to tell Tcl want should happen first:

elseif { not ( [HTTP::uri] ends_with "/" ) } {
   HTTP::redirect "https://[HTTP::host][HTTP::uri]/"
}