"Failed to forward request to apmd" in iRule?

Nope, it was never solved. We opened a support case but never got any solution; The issue is coming up only on high load, and cause of that it is quite hard to pinpoint the exact cause.

What we did is to have a catch around the evaluate and execute it again. It then works in 100 percent of the cases.

if {  [catch {
            ACCESS::policy evaluate -sid $flow_sid -profile $thePolicy session.logon.last.username $currentUser
        } errmsg ] } { 
            if {  [catch {
                ACCESS::policy evaluate -sid $flow_sid -profile $thePolicy session.logon.last.username $currentUser
            } errmsg ] } { 
                log local0.err "Policy failed second time for user $currentUser, giving up"
            }
        }
}