I have faced a problem, which I can't solve, as applying to discover swimlanes plug-in. I was using the event log file that has 1000 process instances and 14000 events and the role set/role partitioning was able to be created correctly. After I deleted 7000 events to check something (I still have 1000 process instances but 7000 events remain), the role partitioning was created as empty. Therefore it shows all activities in one lane in the BPMN model. On the other hand, I get the first 3 process instances and used as input. Although I did not have a correct result from the log that has 1000 process instances, the role partitioning was created successfully from the log that has only 3 process instances. My question is; what causes this kind of problem and how can I solve it?