err tmm1[5010]: 01220001:3

Hello,

I am gettting this error in the logs. Not sure what's missing in the Irule. Can someone help me with this ?

local/tmm1 err tmm1[5010]: 01220001:3: TCL error: IRULE1  - Prerequisite operation not in progress (line 1)     invoked from within "persist add uie [HTTP::cookie SessionId] 1800 "

when HTTP_REQUEST {

if { [HTTP::cookie exists SessionId]} {

persist uie [HTTP::cookie SessionId] 1800

} else {

set sessionid [findstr [HTTP::uri] SessionId 10 ";"]

if { $ != "" } {

persist uie $sessionid 1800

}

}

}

when HTTP_RESPONSE {

if { [HTTP::cookie exists SessionId] } {

persist add uie [HTTP::cookie SessionId] 1800

}

}

}

Thanks