Simulation not working on AS Versions4.9, when we have AS 4.9 & 4.12 Together

I have couple of projects one in 4.9 and other in 4.12. For specific reasons we dont want to update project of 4.9 to 4.12.
I could not work on simulation with 4.9. any specific way to handle this.

I have more AS version installed on my PC and I do not have any problem with simulation. What do you mean, AS4.9 and AS4.12 together? Installed on one PC or installed and running parallelly? What exactly does it mean that it does not work? Any changes in firewall, new antivirus programmed installed in the last days?

I have 4.9 and 4.12 installed . i cant work on 4.9 with simulation. I could not see PLC in run as soon as i turn on simulation. if i uninstall 4.12 this starts working. No Firewall/ antivirus installed in recent days

But you can see ArSim itself when you enable simulation? Do you have Windows security pop up window when you start ArSim for the first time? What is ArSim status and ArSim Start up status line saying? And in tab console, can you see any error message?

Yes i can see the AR SIM Status Running with console saying no error.

If ArSim is ON and running and you can not connect using AS then very likely is problem with PVI manager. Make sure that PVI manager is running, if so check if there is not error , should be not problem but maybe for AS49 you can start PVI manager 4.9 and not PVI manager 4.12