Help setting nextbot sequences

[vingard]

Hi, I'm currently have some issues playing a sequence on a Nextbot.
self:PlaySequenceAndWait( "Specialidle Sit" )

When that runs I get the error in console:
CBaseAnimating::SequenceDuration( -1 ) out of range
The animation does not play, and the ACT_IDLE activity is played instead.

Additionally how do you play sequences without making the nextbot wait (and overriding the activity) I have tried adding this to the nextbot base:
function ENT:PlaySequence( name, speed )

    local len = self:SetSequence( name )
    speed = speed or 1

    self:ResetSequenceInfo()
    self:SetCycle( 0 )
    self:SetPlaybackRate( speed )
end

but it does not seem to work, but maybe that's due to the first issue.

Any help appriciated - thanks.