Hi guys/gals,I've read through all the posts referencing sim1.dll CTDs but have not found any working solution to my CTD. I can connect to multiplayer server, but always get sim1.dll CTD once I hit "Fly" and FSX attempts to start. Some have speculated possible AI aircraft texture issues. How does one troubleshoot and isolate that without going insane? As online flying is a major component of FSX enjoyment, I'm at a loss at why this problem re-occurs even after completing successful FSX Deluxe and Accel repairs. Free Flight works just fine. Details as follows:System Specs:Quad-core AMD Phenom w/ 4GB installed using Win 7 Ultimate 64-bitNVIDIA GeForce GTS 260 and Quadro NVS 290 video cardsNVIDIA Windows 7 (64-bit) 190.62 driverCH Products FS Yoke, Throttle Quadrant, TM Afterburner II joysticksProblem signature:Problem Event Name: APPCRASHApplication Name: fsx.exeApplication Version: 10.0.61637.0Application Timestamp: 46fadb14Fault Module Name: sim1.dllFault Module Version: 10.0.61637.0Fault Module Timestamp: 46fadb59Exception Code: c0000005Exception Offset: 0007af74OS Version: 6.1.7100.2.0.0.256.1Locale ID: 1033Additional information about the problem:LCID: 1033Any ideas/suggestions greatly appreciated!Thanks,Grounded Multiplayer Flyer

Same problem here. I have Crashes to desktop randomly when in multiplayer. They can happen while flying and while on ground; in a long flight or when I haven't even taken off. It's annoying!

Try using a default plane and join any lobby other than the main lobby, and see if the problem persists

0xc0000005 is an access violation - basically something in the process is trying to read memory it does not have access to. A virus certainly could be causing that, although a lot of other things could too, such as unsupported security configuration settings. Do you have UAC enabled? If UAC is enabled, disable it and see if the crash(es) still occur. An aggressive anti-virus program could be preventing access too. This could explain why you and some others get sim1.dll errors and many others do not.If you want to check to see if an AI aircraft is causing the issue (highly unlikely IMHO), just goto the AI tab and turn AI off. If that fixes the problem, then if could be an AI aircraft but again it's not 100% sure as turning off AI will increase your available memory and FPS.Best regards,Jim