Sinumerik Alarm 120309 The selection is not possible. Please close the simulation and repeat the selection.
The simulation is currently active in the program area. A simultaneous editing is not possible.
– Alarm display.
Close the simulation and make the selection again. The alarm disappears automatically as soon as a program is edited or simulated in the program area. The alarm can also be acknowledged manually via diagnostics.
- Siemens Diagnostics Guide by Siemens