IRULE: TCL Error when trying to invoke STREAM expression.

Hello, I know this has been around a while but the single VS solution I use is to place a catch around the stream disable and only enable the stream when the policy is in the allow state using a flag:

when CLIENT_ACCEPTED { set disableStream 1 }
when HTTP_REQUEST { catch { STREAM::disable } }
when ACCESS_ACL_ALLOWED { set disableStream 0 }
when HTTP_RESPONSE { if { $disableStream } { return }
 :
 rest of STREAM code
 :
}

We no longer have errors, hope it helps.