Think I found a small bug (sorry if this was already discovered) in VC 0.950.
The description of <VarName> reads:
Sets the user variable <VarName> to <Value>
You can access the variable in other actions by using {var.variablename}
* If <Value> is omitted then the value of {LastResult} will be used as the <Value>
However, when I omitted the value VC produced the error: Index was outside the bounds of the array
The problem was resolved when I typed in {LastResult} manually.