For those who still have this issue unresolved I came across a possible resolution discussed in the FSXmission.com forum. People who seem to get this problem are those that have set up FSX in a folder that is not the DEFAULT folder.(all the following assume you are running windows XP)
Assuming that this is your problem the resolution to it is as follows:-
A. Uninstall your current FSX SDK installation including any of the SDK service packs you may have added (this does not include the recently recently released FSX service pack only the SDK service packs).
B. Delete the "Microsoft Flight Simulator X SDK" and all its contents that remain from where you installed the SDK (the default is c:\Program Files\Microsoft Games)
For some reason if FSX is not installed in its default folders (ie C:\Program Files\Microsoft Games) with the SDK it will not work. Even if you run the supplied "configsdk.exe".
1. Insert your FSX deluxe disc 1 into your DVD drive open it to display the disc contents and open the "SDK" folder.
2. Run the "setup.exe" and follow the prompts watching for a buttoned option "More Options". Select this to define the path where you want to install the SDK. This phase is critical as the SDK must reside in the same folder as your FSX is installed in. This is best explained by example:-
If you installed FSX in the following path:-
E:\Airport\civilian\Microsoft Flight Simulator X
then the SDK must be installed in the following path:-
E:\Airport\civilian\Microsoft Flight Simulator X SDK
3. Next you need to ensure that the following xml is in your application data folder - "dll.xml". The path is usually along these lines:-
C:\Documents and Settings\<your account name>\Application Data\Microsoft\FSX
(PS if <your account name> above throws you it is the account name you gave yourself when you set up yourself in windows). In my case "Genet". So mine reads:-
C:\Documents and Settings\Genet\Application Data\Microsoft\FSX
4. If it is not go to where your SDK is installed and you will find a copy in the folder called "Mission Creation Kit". In keeping with my example at step 2 your path should look something like this:-
E:\Airport\civilian\Microsoft Flight Simulator X SDK\SDK\Mission Creation Kit
and then copy and paste the file "dll.xml" from this location to your FSX application data folder as discussed at 3.
5. If your application data folder already has a copy of the "dll.xml" file right click on it and select the "edit" option it will open up[ in a new window and you will need to read through it line by line to ensure that the following lines exist EXACTLY as below:-
<Launch.Addon>
<Name>Object Placement Tool</Name>
<Disabled>False</Disabled>
<ManualLoad>False</ManualLoad>
<Path>..\Microsoft Flight Simulator X SDK\SDK\Mission Creation Kit\object_placement.dll</Path>
</Launch.Addon>
If these lines do not exist then insert them ensuring that you do not embed it within another addon launch sequence and ensure it is all before:
</SimBase.Document>
which must remain the last line in this file.
Once done save the "dll.xml".
6. Run FSX and when you click the fly now button and the program starts usually with you in the cockpit go to the drop down main menu or if it is not present press the [ALT] button and you should see a new option called "Tools" and the mission editor is therein called "Object placement tool":thumb:
7. If this is not the case this may solve the problem. Go to where you have installed your SDK and go to the folder named "SDK" open it and within is a file called "configsdk.exe" In keeping with my examples above the path should look something like this:-
E:\airport\civilian\Microsoft Flight Simulator X SDK\SDK\configsdk.exe
Double click this to run it. A DOS window will open and display a question, type in "y" for yes and press your [Return] key and let it run to completion.
8. Restart FSX as at 6.. If this does not resolve your problem with mission editing I'm sorry I've failed you.:red: