Trouble running example B1

I believe the issue I am have is during the building of example B1 i receive a warning C:\Users\Andrew\Desktop\Geant4\geant4_10_05-install\include\Geant4\G4MergeMode.hh(74): warning C4715: ‘G4Accumulables::GetMergeFunction’: not all control paths return a value [C:\Users\Andrew\Desktop\Geant4\B1-build\exampleB1.vcx
proj]
Attached is a B1output.txt (8.6 KB) from the command prompt.
I am using window 10 with VS 2019 with cmake 3.15.1

Hello,
The warning from G4Accumulables is harmless; we will anyway fix it. Could you type after the prompt Idle>
/run/beamOn 10

Does this command start event processing?