Finally got to my FSX pc. Checked applications error log and all are ai_player.dll Not being a wiz when it comes to the finer points of software, what exactly does that tell me apart from the fact this is the culprit (i assume).More to the point what do i do with this information? Should also tell you my brief PC desc:core i7 950 (not o.c.)rampage iii extreme m/b2 x gtx460 fact. o.c. (sli enabled)6gb. G.skill ddr3-1600 pc3-12800 (not o.c.)coolermaster silent pro-1000 psuwin7 - 64bit

Update: Just loaded a flight and then exited FSX and no crash. Loaded another & another, moved to different camera views, taxid around and then exited and each time no crash???

Finally got to my FSX pc. Checked applications error log and all are ai_player.dll

Those are the ones I get -- no others, but those on perhaps 90% of FSX terminations. In my case it is something to do with Ultimate Traffic 2. Seems that if FSX terminates during some crucial interaction between UT2Services.exe and SimConnect, the latter causes the AI_Player crash because the part of FSX is tries to write to has terminated and is no longer in memory. It indicates that the multi-threading aspects of FSX aren't really as well coordinated and synchronised as they should be.If this is your cause too, there's not a lot you can do about it except possibly to try to remember to shut UT2 down before FSX. Generally I don't bother. The only thing lost by FSX crashing on termination is that it then doesn't usually save its CFG file, so you lose any changes you made to its options during that session. Since I prefer editing FSX.CFG directly this doesn't really bother me.RegardsPete

Thanks Pete, for explaining things for me in simpler terms. So if i don,t mind a dialog box at the finish of my flight now and again, then there is no real impending disaster around the corner? Coinsidentally i have another error in the log that is a 'Side By Side' error FSUIPC4.dll and i think it coinsides with another little thing that happens when i have to end a flight before it is finished and i have a real hard time shutting down RC4. After several attempts this same dialog comes up and i choose shut down to stop RC4. I therefore assume this is RC4 related and not FSUIPC?

Coinsidentally i have another error in the log that is a 'Side By Side' error FSUIPC4.dll and i think it coinsides with another little thing that happens when i have to end a flight before it is finished ..

No, the SideBySide "errors" occur during FSX + FSUIPC start-up, and are merely due to the way FSUIPC tests for versions of SimConnect so that it can find the latest one to work with, whether the original, SP1, SP2, Acceleration, ESP or Prepar3D. The errors are unavoidable with "Probing" manifests to see if they are viable -- even the SimConnect author could not find a way around those. They are documented in the FSUIPC4 User Guide in order to allay folks fears.However, later last year, well after the 4.60a release, I did find a better way and that is incorporated in all recent updates such as the version 4.669 currently available from the Download Links subforum on my Support Forum.

... and i have a real hard time shutting down RC4. After several attempts this same dialog comes up and i choose shut down to stop RC4. I therefore assume this is RC4 related and not FSUIPC?

What dialog is that? You mean FSX crashing like at termination? And this happens even when simply ending a flight, to go back to the main flight selection menu? That's not right.Pete

What dialog is that? You mean FSX crashing like at termination? And this happens even when simply ending a flight, to go back to the main flight selection menu? That's not right.Pete

No, sorry for not being clear. Sometimes for whatever reason i cannot finnish my flight so i just save the flight at that point to resume another time then just exit FSX normally. after this, from my desk top i see RADAR CONTACT still active on the task bar due to the fact i did not finish my flight and receive 'taxi to the gate' clearance after which as you know, you hit key 3 to exit RC4. So when i try to shut it down, most times i will get that same dialog box we are discussing when exiting FSX . Only it is refering to RADAR CONTACT. Sometimes in this situation i don't even get this dialog box and on rare occations, have to use my task manager to make RC4 shut down.

No, sorry for not being clear. Sometimes for whatever reason i cannot finnish my flight so i just save the flight at that point to resume another time then just exit FSX normally. after this, from my desk top i see RADAR CONTACT still active on the task bar due to the fact i did not finish my flight and receive 'taxi to the gate' clearance after which as you know, you hit key 3 to exit RC4. So when i try to shut it down, most times i will get that same dialog box we are discussing when exiting FSX . Only it is refering to RADAR CONTACT. Sometimes in this situation i don't even get this dialog box and on rare occations, have to use my task manager to make RC4 shut down.

The problem there is simply that RC is in a loop waiting for a response and doesn't monitor the situation regarding its link with FS. So it stays in that loop forever, or tries to access the shared memory which may by now be inaccessible. RC is written in VB and is, I think, single-threaded. There's no extra sophisticated stuff in its loops where it knows what you are doing. Your procedure should always be to close it down first.RegardsPete

Thanks Pete. Will do.

Hey,I have had the same problem ever since I installed the PMDG 737 NGX, no crashes in game just when i exit out of it it says not responding, then sometimes,...FSX has stopped working.....any help???

If you're using FSInn, disable "tuner" in settings, that will usually fix it.