Hi all,
I have tried to plot a histogram  for delay in a simple inverter after running the monte carlo trans in scs file, I  start running my  script in ocean to view the histogram results by using:

MonteExpr("delay" 'delay(?wf1 in ?value1 0.6 ?nth1 5 ?edge1 'rising ?wf2 out ?value2 0.6 ?nth2 5 ?edge2 'falling))

histogram("delay" ?numBins 100 ?density t)

but apparently something is wrong and I can not see the histogram, let me tell you about the warning messages

Monte carlo results has not been selected or invalid.

Please advice to help me to sort this issue.

Thanks
Leila