I wrote an absolute minimal DirectX program, and got strange behaviour: without errors it doesn't work, and with it does!

First a normal build and run.

Build output:

------ Build started: Project: DirectY, Configuration: Release x86 ------

C:\Program Files\Microsoft F#\v4.0\fsc.exe -o:obj\x86\Release\DirectY.exe --debug:pdbonly --noframework --define:TRACE --doc:bin\Release\DirectY.XML --optimize+ --platform:x86 -r:"C:\Program Files\Programmeren\Taal\F#\v4.0\bin\FSharp.Core.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2902.0\Microsoft.DirectX.Direct3D.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2911.0\Microsoft.DirectX.Direct3DX.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2902.0\Microsoft.DirectX.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\mscorlib.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Core.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Drawing.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Numerics.dll" -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Windows.Forms.dll" --target:exe --warn:3 --warnaserror:76 --vserrors --LCID:1033 --utf8output --fullpaths --flaterrors "C:\Documents and Settings\Biep\Local Settings\Temp\.NETFramework,Version=v4.0.AssemblyAttributes.fs" Program.fs

DirectY -> c:\docs\Werk\Programmeren\F#\Sprite\DirectY\bin\Release\DirectY.exe

========== Build: 1 succeeded or up-to-date, 0 failed, 0 skipped ==========

If I run under debug, I get this:

'DirectY.exe' (Managed (v4.0.30319)): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

'DirectY.exe' (Managed (v4.0.30319)): Loaded 'c:\docs\Werk\Programmeren\F#\Sprite\DirectY\bin\Release\DirectY.exe', Symbols loaded.

'DirectY.exe' (Managed (v4.0.30319)): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\FSharp.Core\v4.0_4.0.0.0__b03f5f7f11d50a3a\FSharp.Core.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

'DirectY.exe' (Managed (v4.0.30319)): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.

The program '[2584] DirectY.exe: Managed (v4.0.30319)' has exited with code 1073807364 (0x40010004).

The program runs and uses a lot of CPU, but doesn't show a window, nor any output if <i>any<i> reference to DirectX is made: <ul><li>let pparams = Microsoft.DirectX.Direct3D.PresentParameters() // And nothing else, no device or anything </li><li>let m = new Microsoft.DirectX.Matrix() // Again: and nothing else </li><li>let am = async {return new Microsoft.DirectX.Matrix()} // And 'am' is nowhere executed. </li></ul> The .fsproj file contains the line If I remove the bit 'ToolsVersion="4.0"', the situation is completely different: Build output: ------ Build started: Project: DirectY, Configuration: Release x86 ------ Could not locate the .NET Framework SDK. The task is looking for the path to the .NET Framework SDK at the location specified in the SDKInstallRootv2.0 value of the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework. You may be able to solve the problem by doing one of the following: 1.) Install the .NET Framework SDK. 2.) Manually set the above registry key to the correct location. C:\Program Files\Microsoft F#\v4.0\fsc.exe -o:obj\x86\Release\DirectY.exe --debug:pdbonly --noframework --define:TRACE --doc:bin\Release\DirectY.XML --optimize+ --platform:x86 -r:"C:\Program Files\Reference Assemblies\Microsoft\FSharp\2.0\Runtime\v2.0\FSharp.Core.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2902.0\Microsoft.DirectX.Direct3D.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2911.0\Microsoft.DirectX.Direct3DX.dll" -r:"C:\WINDOWS\Microsoft.NET\DirectX for Managed Code\1.0.2902.0\Microsoft.DirectX.dll" -r:C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\mscorlib.dll -r:"C:\Program Files\Reference Assemblies\Microsoft\Framework\v3.5\System.Core.dll" -r:C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.dll -r:C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Drawing.dll -r:C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Numerics\v4.0_4.0.0.0__b77a5c561934e089\System.Numerics.dll -r:C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Windows.Forms.dll --target:exe --warn:3 --warnaserror:76 --vserrors --LCID:1033 --utf8output --fullpaths --flaterrors Program.fs FSC: warning FS0217: The referenced or default base CLI library 'mscorlib' is binary-incompatible with the referenced library 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Numerics\v4.0_4.0.0.0__b77a5c561934e089\System.Numerics.dll'. Consider recompiling the library or making an explicit reference to a version of this library that matches the CLI version you are using. DirectY -> c:\docs\Werk\Programmeren\F#\Sprite\DirectY\bin\Release\DirectY.exe ========== Build: 1 succeeded or up-to-date, 0 failed, 0 skipped ========== Now if I debug (F5), I get: 'DirectY.exe' (Managed (v2.0.50727)): Loaded 'C:\WINDOWS\assembly\GAC_32\mscorlib\2.0.0.0__b77a5c561934e089\mscorlib.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled. 'DirectY.exe' (Managed (v2.0.50727)): Loaded 'C:\WINDOWS\assembly\GAC_MSIL\mscorlib.resources\2.0.0.0_nl_b77a5c561934e089\mscorlib.resources.dll' 'DirectY.exe' (Managed (v2.0.50727)): Loaded 'c:\docs\Werk\Programmeren\F#\Sprite\DirectY\bin\Release\DirectY.exe', Symbols loaded. 'DirectY.exe' (Managed (v2.0.50727)): Loaded 'C:\WINDOWS\assembly\GAC_MSIL\FSharp.Core\2.0.0.0__b03f5f7f11d50a3a\FSharp.Core.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled. 'DirectY.exe' (Managed (v2.0.50727)): Loaded 'C:\WINDOWS\assembly\GAC_MSIL\System\2.0.0.0__b77a5c561934e089\System.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled. The program '[4856] DirectY.exe: Managed (v2.0.50727)' has exited with code 0 (0x0). When running with the debugger (F5), I get a LoaderLock Exception. Program output: Unhandled Exception: System.IO.FileLoadException: Mixed mode assembly is built against version 'v1.1.4322' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information. at Spel.beeld(String[] args) When running without debugger (Ctrl+F5) the program seems to work fine. So it seems I can choose between error messages with a working program, and no errors, but a non-working program.. :-( Any suggestions as to how to get decent behaviour on both sides at the same time? (And how to switch off the LoaderLock MDA just for this project?) Thanks, Biep.