Error Creating Display: Comparison method violates its general contract!

FazlaH20

Hello all, I am new user of Rapid miner and Rapid Prom. I have imported the xes file of the event log and tried to generate several petrinet like alpha inductive miner etc. but after running the model I find this error during the result analysis. "executing background job 'Creating Display: java.lang.IllegalArgumentException: Comparison method violates its general contract!"

i don't understand. should I download any extension ? please help me out.