Help Trying to add DistanceConstraint for my TearableCloth but getting IndexOutOfRange

[snowtv]

I'm following the example on the official document, here is the jist of my current method:

Code:

// get a hold of the distance constraint
        var distanceConstraints = colon.GetConstraintsByType(Oni.ConstraintType.Distance) as ObiConstraints<ObiDistanceConstraintsBatch>;

        // create a new distance constraints batch
        var batch = new ObiDistanceConstraintsBatch();

        // Add a constraint for the pair
        batch.AddConstraint(new Vector2Int(particleSolverIndexA, particleSolverIndexB), 0);

        // set the amount of active constraints in the batch to 2 (the ones we just added).
        batch.ActivateConstraint(0);

        // append the batch to the pin constraints:
        distanceConstraints.AddBatch(batch);

        // this will cause the solver to rebuild distance constraints at the beginning of the next frame:
        colon.SetConstraintsDirty(Oni.ConstraintType.Distance);

Basically my method will first find the solver indexes of two particles closest to the given world positions, then using the above code to add DistanceConstraint between them.

I removed the part of the example where it clears the entire constraint batches first, because I don't wanna remove all the existing DistanceConstraint.

Is there something wrong in the above code? Or I'm not getting the correct solver index for my particles?