aws
dotnet-lambda-test-tool-6.0.exe fails with BEX64 Application exception always when launced via Visual Studio, but does not when just ran independently.
Describe the bug
I am trying to set up a new system and cannot get the dotnet-lambda-test-tool-6.0 exe working on it via Visual Studio, where I need it to work so that I can use it to debug and develop Lambda Functions.
Everytime I run it via VS2022 Community Edition, I get the following error in the Event Viewer:
Faulting application name: dotnet-lambda-test-tool-6.0.exe, version: 0.0.0.0, time stamp: 0x67ab0000 Faulting module name: ntdll.dll, version: 10.0.22621.5124, time stamp: 0x82bfa2b9 Exception code: 0xc0000409 Fault offset: 0x00000000000a4ad6 Faulting process id: 0x0x6A70 Faulting application start time: 0x0x1DBA541428CA0A6 Faulting application path: C:\Users\me.dotnet\tools\dotnet-lambda-test-tool-6.0.exe Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll
With Further info: Fault bucket 1430445718552608279, type 5 Event Name: BEX64 Response: Not available Cab Id: 0
Problem signature: P1: dotnet-lambda-test-tool-6.0.exe P2: 0.0.0.0 P3: 67ab0000 P4: ntdll.dll P5: 10.0.22621.5124 P6: 82bfa2b9 P7: 00000000000a4ad6 P8: c0000409 P9: 0000000000000030 P10:
System Info:
OS: Windows 11 Pro Version: 23H2 Installed: Just reinstalled today in an effort to get it working (failed) OS Build: 22631.5126
.Net Frameworks installed 6.0.414 [C:\Program Files\dotnet\sdk] 9.0.201 [C:\Program Files\dotnet\sdk]
Visual Studio Version Microsoft Visual Studio Community 2022 (64-bit) - Current Version 17.13.5
Device: Processor: 13th Gen Intel(R) Core(TM) i9-13900H 2.60 GHz RAM: 32.0 GB (31.7 GB usable) System type: 64-bit operating system, x64-based processor
With it failing on my PC no matter what I found online and tried, I thought I'd punt and reformat the PC. I really need to get this working, so I've actually re-imaged my PC to a fresh windows install again, figuring something must have been off with my Windows Install, BUT I've come to find that this EXE still has whatever issue it has - behaves/fails the same way.
Regression Issue
- [ ] Select this option if this issue appears to be a regression.
Expected Behavior
I expected to see how it used to work. Command window pops up, it shows the process looking for the dotnet-lambda-test-tool and then a browser tab opens up and shows me the AWS Lambda Test Tool page.
Current Behavior
Command window disappears quickly, and I see the following:
If I run it via VS, I get a DOS command window for a fleeting moment, and then in Visual Studio, it shows this in the Output pane:
'dotnet-lambda-test-tool-6.0.exe' (CoreCLR: DefaultDomain): Loaded 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.22\System.Private.CoreLib.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'dotnet-lambda-test-tool-6.0.exe' (CoreCLR: clrhost): Loaded 'C:\Users\ME.dotnet\tools.store\amazon.lambda.testtool-6.0\0.16.2\amazon.lambda.testtool-6.0\0.16.2\tools\net6.0\any\Amazon.Lambda.TestTool.BlazorTester.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'dotnet-lambda-test-tool-6.0.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.22\System.Runtime.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'dotnet-lambda-test-tool-6.0.exe' (CoreCLR: clrhost): Loaded 'C:\Users\ME.dotnet\tools.store\amazon.lambda.testtool-6.0\0.16.2\amazon.lambda.testtool-6.0\0.16.2\tools\net6.0\any\Amazon.Lambda.TestTool.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'dotnet-lambda-test-tool-6.0.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.22\System.Console.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
The program '[9104] dotnet-lambda-test-tool-6.0.exe' has exited with code 3221226505 (0xc0000409).
Help?!? Also, please let me know if there is anything else that I can provide.
The strange thing is that I can simply double-click on the exe and it will create a command window and executes fine, show its usual content momentarily, and then create a new browser tab that's ready to receive the Lambda settings / config / data that I want to test with. This is a good sign but not useful, as I need it to start via Visual Studio so I can debug the lambda processes I work on.
Reproduction Steps
As stated above. Just run the Mock Test Lambda Tool via Visual Studio. It doesn't work, and has event viewer messages showing the info given above.
Possible Solution
I've tried everything I can find to fix this. Now I think I'll have to move back to my old PC so that I can work. Bummed.... :(
Tried sfc /scannow to look for system file issues. None were found, and still fails after resetting to freshly re-installed OS. Tried running in compatability mode. Tried running VS as an admin. Tried updating, uninstalling, reinstalling everything I can think of / see that could be related. Stumped.
Additional Information/Context
None.
AWS .NET SDK and/or Package version used
AWS Toolkit - ver 1.67.0.0. dotnet-lambda-test-tool-6.0.exe ver 0.16.2
Targeted .NET Platform
.Net 6
Operating System and version
Windows 11 Pro Version: 23H2
@CurtisHerrick Could you try a different machine or an EC2 instance? Refer to similar issue https://learn.microsoft.com/en-us/answers/questions/1878248/after-update-visual-studio-17-10-5-to-17-11-0-our. Could you also try updating your .NET runtime and SDK(s) installed on your machine?
Thanks, Ashish
I do have another machine where it is working, and I'm attempting to duplicate all the config, but it is rather difficult, as Visual Studio Community has moved on in version, and the new version requires things that the old one doesn't. That said, other developers around me can use the AWS lambda testing tool just fine on the newer versions of Visual Studio. Really quite stumped.
I am reinstalling VS 2022 Community right now, and will upgrade anything I can find to.
I've been through this process on this machine twice now, and even reinstalled Windows. In doing so, all the installs were the latest downloads, etc.
@CurtisHerrick Please confirm if you were able to resolve the issue and if it could be closed.
I was not able to resolve this and literally replaced my PC with a different one so that I could do my work. One hunch I have is that it works on my PC having an Intel Core I9 processor. It did not work on the PC I logged the issue with no matter how many times it was reimaged, etc. That was an I9, but not Core. It was something like a "Force", or something. I do not have the PC to confirm the naming, but it was not an Intel I9 core for sure.
Thanks, Curtis Herrick
On Wed, May 21, 2025, 6:11 PM Ashish Dhingra @.***> wrote:
ashishdhingra left a comment (aws/aws-lambda-dotnet#2029) https://github.com/aws/aws-lambda-dotnet/issues/2029#issuecomment-2898675315
@CurtisHerrick https://github.com/CurtisHerrick Please confirm if you were able to resolve the issue and if it could be closed.
— Reply to this email directly, view it on GitHub https://github.com/aws/aws-lambda-dotnet/issues/2029#issuecomment-2898675315, or unsubscribe https://github.com/notifications/unsubscribe-auth/AGEVSHJJA4OKSJLE5VOFZ2D27SXVDAVCNFSM6AAAAAB2ONPICKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDQOJYGY3TKMZRGU . You are receiving this because you were mentioned.Message ID: @.***>
