Hi,I've posted this in the Digital Aviation forum but I did not receive any rely so far. Hope to have better chance here.I recently moved from XP PRO 32-bit to Windows 7 64-bit (fresh install of Win 7) and re-installed FSX, Acceleration and the Piper Cheyenne V4.00. I am administrator, FSX is ran as administrator and the Cheyenne installer was ran as administrator.My problem: Everytime I try to select the Piper Cheyenne V4.00 in FSX (any model), under Windows 7 64-bit, I get an APPCRASH in FSX caused by "DA.PA31Avionics.DLL". I cannot understand why. Could anyone give me a clue ?FSX runs fine otherwise in Win 7 and I never had any problem with the Cheyenne under Windows XP Pro SP3.Thank's in advance,Normand.

Hi,I've posted this in the Digital Aviation forum but I did not receive any rely so far. Hope to have better chance here.I recently moved from XP PRO 32-bit to Windows 7 64-bit (fresh install of Win 7) and re-installed FSX, Acceleration and the Piper Cheyenne V4.00. I am administrator, FSX is ran as administrator and the Cheyenne installer was ran as administrator.My problem: Everytime I try to select the Piper Cheyenne V4.00 in FSX (any model), under Windows 7 64-bit, I get an APPCRASH in FSX caused by "DA.PA31Avionics.DLL". I cannot understand why. Could anyone give me a clue ?FSX runs fine otherwise in Win 7 and I never had any problem with the Cheyenne under Windows XP Pro SP3.Thank's in advance,Normand.

There are several possible reasons for these crashes, including having REX installed, having ASA installed and running, having a weather program working, using AI made back in the FS9 and FS8 days, and not having the proper dotnet version installed (Version 2). I did a Google search for DA.PA31Avionics.DLL and came up with several discussions at several FS forums and some of the recommended fixes worked for some but not all so I highly recommend you check out some of the discussions and see if any match your FSX configuration and or OS config. Sorry I couldn't find a more definitive solution to your problem. If you do find a fix, I would recommend you post it here so that it might help others in the future. I have been seriously considering buying this aircraft and I might run into the same problem...Best regards,Jim

There are several possible reasons for these crashes, including having REX installed, having ASA installed and running, having a weather program working, using AI made back in the FS9 and FS8 days, and not having the proper dotnet version installed (Version 2). I did a Google search for DA.PA31Avionics.DLL and came up with several discussions at several FS forums and some of the recommended fixes worked for some but not all so I highly recommend you check out some of the discussions and see if any match your FSX configuration and or OS config. Sorry I couldn't find a more definitive solution to your problem. If you do find a fix, I would recommend you post it here so that it might help others in the future. I have been seriously considering buying this aircraft and I might run into the same problem...Best regards,Jim

Problem solved !!Thank you Jim for refering to Google. I feel ashamed of not having tought of doing a Google search on this, but if you don't mind, I'll put the blame on my half a century age :( Since I don't have (yet) any other 3rd party software installed for FSX, it had to do with the basic installation of the Cheyenne, and indeed it did. I was missing the TCAS2V7.DLL and .INI files (they are not included in my copy of the Cheyenne 4 installation download).After installing the Cheyenne, I initially made the mistake of installing the TCAS files inside the "Gauges" folder, which created the problem. But they actually go inside the FSX's root folder. No more APP CRASH now and the Cheyenne performs very well under FSX/Acceleration and Windows 7 (based on a 30 minutes VFR flight). The Cheyenne is my favorite GA aircraft and I highly recommend it if you like twin turboprops. It is a joy to fly when one follows the proper procedures and the owner's manual is well written. I've been flying it since March 2008 on my XP Pro/FSX machine and now I'll be able to continue enjoying it under Windows 7 64-bit.Thank's again Jim, the word "Google" gave me all I needed to hunt for the correct fix.Best regards,Normand.

Depending on where you purchase the DA Cheyenne, you might want to pick up a copy of the latest installer, as I believe it sorts out the TCASv2.7.dll crash error... I vaguely remember this when V4 came out and new installers were released. The issue was reported and I believe DA responded with a fixed installer...The Cheyenne was a great one in FS9 when it came out, and the FSX variant too... I used it a fair bit, though it sees daylight a little less these days, given the amount of competition it now has with the JS41 to name just one...Andrew

Problem solved !!Thank's again Jim, the word "Google" gave me all I needed to hunt for the correct fix.Best regards,Normand.

Glad you were able to find a fix so quickly Normand. I like to use Google as it searches all the FS forums. I was getting ready to suggest you reinstall the aircraft as it did sound like FSX was "calling" for a file or gauge and couldn't find it so it caused the crash. Thanks for posting back as I'm sure this issue will be a problem for others.Best regards,Jim

Depending on where you purchase the DA Cheyenne, you might want to pick up a copy of the latest installer, as I believe it sorts out the TCASv2.7.dll crash error... I vaguely remember this when V4 came out and new installers were released. The issue was reported and I believe DA responded with a fixed installer...The Cheyenne was a great one in FS9 when it came out, and the FSX variant too... I used it a fair bit, though it sees daylight a little less these days, given the amount of competition it now has with the JS41 to name just one...Andrew

Hi Andrew, I followed your suggestion and downloaded the latest Cheyenne V4.0 installer from SimMarket. At least, I won't have to scratch my head next time I re-install the Cheyenne.Best regards,

Sorry that this caused problems. One of the things you just miss when testing and cannot always start with a blank FS...Thank you for the help provided to visitors of this forum.