[SOLVED] Alarm Snooze Rule Error

I’m setting up an openhab panel which amongst other things has an alarm clock for the bedroom
It needs a snooze button (or I could just get up but hey…)
It’s a simple switch that changes squeezebox state from mute off to on
I need it to go from on to off at 10minutes
It’s working but I am getting the following error

[ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Snooze Alarm': An error occurred during the script execution: Couldn't invoke 'assignValueTo' for feature JvmVoid:  (eProxyURI: snooze.rules#|::

Rule is this (I’ve edited out some as it didn’t work and not sure necessary)

rule "Snooze Alarm"
    Item squeezebox_squeezeboxplayer_BB59203A_FECF_4B95_A3BF_05F6FFC3AC82_b827eb45808d_mute changed
    if (squeezebox_squeezeboxplayer_BB59203A_FECF_4B95_A3BF_05F6FFC3AC82_b827eb45808d_mute.state == ON)
    myTimer = createTimer(now.plusMinutes(10))[|

Any help appreciated

Is myTimer declared outside the body of the rule? E.g.

var Timer myTimer

Ah no - that will be it then I guess
Thanks in Advance

Have you considered Expire Binding ? It should simplify lots of rules like these.