Problem about inactivate msc

Hi there, GEANT4 users. I encountered an issue while using GEANT4 10.06 for simulation. I modified the code based on ExampleB1 and attempted to disable multiple scattering interactions for protons using “/process/inactivate msc proton” in my .mac file. However, I encountered the following error:

Have any of you experienced this problem? How did you resolve it? Interestingly, when I ran the same code on GEANT4 10.07, I encountered no errors.