If you have been using BER analyzer 1 or 2 results for your sweep graph, then I don’t think that’s the reason. Maybe it is because of the power increase. I think you can open my file if you open it with the software (first open the software and the open it by “open” option from the file menu). If you manage to open it, you can do the simulation once with it and see if you have the same problem. I didn’t face any problem during my simulation with it, though.