Two problems with my SimPowerSys model: Recursion limit, line disconnected automatically

I have a large power system model made by Simulink and SimPowerSys libraries: several synchronous machines, lots of loads, many power electronics switch. I am using MATLAB 2012a to run it, with accelerator mode.

The wired thing is that - if I open the model and SAVE it(no matter I change something in the model or not) and then run it, everything goes smoothly and no error message and nothing else. - BUT, if I open the model and run it directly without saving the model before running, two problems occurs:

1. The following error messages shown in command window. ------------------------------------------------ In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 81 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 222 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SwitchesInit.p>SwitchesInit at 289 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\getSPSmaskvalues.p>getSPSmaskvalues at 30 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SwitchesEnables.p>SwitchesEnables at 7 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\ThreePhaseFaultCback.p>ThreePhaseFaultCback at 56 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 81 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 222 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SynchronousMachineInit.p>SynchronousMachineInit at 93 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 81 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 222 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SynchronousMachineInit.p>SynchronousMachineInit at 93 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 Warning: Maximum recursion limit of 500 reached. Use set(0,'RecursionLimit',N) to change the limit. Be aware that exceeding your available stack space can crash MATLAB and/or your computer.

. . . In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SPSrl.p>SPSrl at 222 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\private\SynchronousMachineInit.p>SynchronousMachineInit at 93 In C:\Program Files\MATLAB\R2012a\toolbox\physmod\powersys\powersys\powericon.p>powericon at 99 Warning: Error evaluating 'LoadFcn' callback of Three-Phase Breaker block (mask) 'MVAC_V3_071012_1/Subsystem43/b_Z1s'. -------------------------------------------------------- This happens to many of the models, such as synchronous machine, three-phase breaker, transformer, etc. I don't know what is the problem.

2. All the lines connected the "from" block and the three-phase breaker are disconnected automatically. Do not know why.

Any help will be highly appreciated!