Error during snapshots launch simulator

By selecting test module  in snapshots  for  simulating the fulladder program , I have the follwing error.

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 ERROR;

ncsim: *F,NOLICN: Unable to checkout license for the simulation. Use ncsim -MESSAGES for more information. (flag - 2) 'lic_error -15'.
ncsim: Memory Usage - 38.6M program + 20.3M data = 58.9M total (59.4M Peak)
ncsim: CPU Usage - 0.0s system + 0.0s user = 0.0s total (30.1s, 0.0% cpu)
ncsim -gui -cdslib /home/cadence/fa/faac.lib -logfile /home/cadence/fa/ncsim.log -errormax 15 -status worklib.fa_test:module
nclaunch> ncsim(64): 15.20-s051: (c) Copyright 1995-2018 Cadence Design Systems, Inc.

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There is a pop-up window to simulate the program. but I didn't get.

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Program

module fa(a,b,c,s,cout);
input a,b,c;
output s,cout;
assign s= a^b^c;
assign cout=(a&b)|(b&c)|(c&a);
endmodule

Testbench program

module fa_test;
reg a,b,c;
wire s,cout;
integer correct;
fa fulladder(a,b,c,s,cout);
initial
begin
correct=1;
#5 a=1; b=1;c=0; #5;
if((s!=0) || (cout!=1))
correct=0;
#5 a=1; b=1;c=1; #5;
if((s!=1) || (cout!=1))
correct=0;
#5 a=0; b=1;c=0; #5;
if((s!=1) || (cout!=0))
correct=0;
#5 $display ("%d", correct);
end
endmodule