I am working on the design of an oscillator. I have attached a snapshot of the schematic to this message. In the schematic I have used an isource instance I40 which remains open. The oscillator build up is varying depending on  the frequency that I give in I40 instance. In this case the oscillator is building up faster with increase in frequency in I40 instance. I am not able to contemplate why the oscillation build up is dependent on the frequency in I40 which is no where connected to the circuit.

I am running transient analysis. Please find the schematic and netlist attached to this message.

By having an active current source driving an open circuit you are causing those nodes to shoot up to extremely high voltages. This will destroy the error control of the simulator unless you take certain steps to counter it.

Don't do that.

Also, don't ask simulation questions in the design boards.

-Ken