3-phase circuit breaker block causing lack of of load flow convergence!

I am trying to simulate a loss of load scenario with two 13.8 kV 100 MVA generators connected to a 25 kV network (modified from power_turbine example, I split the 200 MVA generator into 2 100 MVA units). Everything with the load flow works well as expected as I incrementally build my network from the basic example. However, when I connect a 3-phase circuit breaker to isolate one of the generators at a given point in the simulation, I get an unexpected 'failed to converge' message!

 I have tried to attach the modified model (slx format) without succcess, I get this error message:

File format is unsupported. Use any of these formats: .bmp, .csv, .fig, .gif, .jpg, .jpeg, .m, .mat, .mdl, .pdf, .png, .txt, .xls, .zip.

Any pointers to the source of error and how to get past it will be highly appreciated. Cheers!

Jim