Newbie Question about Spice Simulator

Hi, I am new to KICAD. I am currently trying to simulate my circuit which includes the BQ35100PW that I’ve donwloaded its library. I am getting this error:

Do you have any idea about how to resolve this?

This is mostly a duplicate of this other topic you opened:

As a starting point, I’d encourage you to go through the tutorial for KiCad simulation here: KiCad Eeschema as GUI for ngspice, tutorial for setting up the simulation

If you have questions as you work through it or on your own simulation, please post what you have done (including the entire project folder zipped up) and what happened/what you expected to happen. That way the community here has the best chance of helping you.

What do you need to simulate a circuit?

You will need a schematic of your circuit, including all symbols, connections etc.

And you will need spice models for all elements. For simple devices like R, L, C these models are provided intrinsically by the simulator. For integrated circuits, these models are typically provided by the semiconductor companies making the devices.

Talking about the BQ35100, you may look up the TI web pages at BQ35100 data sheet, product information and support | TI.com. Unfortunately there seems to be no spice model available. If TI cannot provide you with such a model (you may ask them), you cannot simulate the circuit with KiCad/ngspice (and not with any other spice simulator).