irule execution error

If you don't have any logs being created for TCL errors then you are going to have to create the logs yourself within the iRule to show which part of the iRule you have got to. Let me show you an example:

when HTTP_REQUEST {
  log local0.debug "[virtual]:[IP::client_addr] test 1"
 .. ( other iRule commands here )
  log local0.debug "[virtual]:[IP::client_addr] test 2"
}

If you see test1 in the logs and not test2 then you know it failed in the middle somewhere, just move the test2 log and work it out to find where it is failing.