Q:   Why in some cases the CIR model does not work and the VCCS model works, or vice versa?

A:   The explanation is that these software models were developed independently. There are a lot of heuristics that are in one model and not in the other. It is important to note that OneLiner is a short circuit program, and not a time-domain simulator like the EMTP. Time domain simulators may have strategies to deal with CIRs that are impossible to carry out by OneLiner.