SABER仿真问题请教！

我做了一个UC3854的仿真电路，仿真电路如图所示，电路倒是能够运行仿真，但是怎么仿不出结果呢？
各位高手请指点。出错信息如下：


Loading dynamic libraries...
saber
Host image, unknown running Windows NT 5.1 Ver. 2600 Service Pack 1
Wed May 26 17:01 2004
> dc
The no_ramping algorithm failed. Trying the dyn_ramping algorithm.
Succeeded with the dyn_ramping algorithm.
execution time= 0.484 sec.
> tr (tend 25m,tstep 1000n
*** ERROR "ALG_NO_SOLUTION" *** Cannot find nonlinear system solution.
*** ERROR "ALG_SINGULAR_JACOBIAN" *** Singular Jacobian matrix.
Some possible causes for a singular Jacobian matrix:
- Model operating outside of its intended region of operation.
- Node/subsystem with no connection to the reference (floating).
- Current loops (voltage sources/inductors in parallel).
- Missing equation and/or missing variable reference.