New user to electric and flip-flops.

I've just started using Electric for class, and I'm having trouble with 
flip-flops. I cannot run any simulations with flip-flops if I hook 
anything into the CLR port. The simulation fails to run with this error...

Compiling VHDL in cell 'CPU_Handshake_(D_FF){vhdl}' ...*****  UNRESOLVED 
REFERENCES *****
drff, 1 time(s)
 Done, created cell 'CPU_Handshake_(D_FF){net.als}'
Simulating netlist in cell 'CPU_Handshake_(D_FF){net.als}'
ERROR: Model 'DRFF' not found, simulation aborted

If I try to use a T FF, it fails to find the model TRFF. Any help would 
be appreciated. :)