Regression in Extension Bundle 1.165.50 on Linux: kernel32.dll DllNotFoundException prevents Logic Apps execution

[int292]

Describe the Bug

All Logic App integration tests are currently failing due to a known kernel32 platform/runtime issue during shared test host initialization. Since every integration test uses the same startup infrastructure, initialization fails before individual workflows execute, causing a full-suite failure. This is an infrastructure/runtime problem rather than a workflow logic regression.

Extension Bundle Microsoft.Azure.Functions.ExtensionBundle.Workflows version 1.165.50 appears to contain Windows-only performance counter code that is executed on Linux.
This causes System.DllNotFoundException for kernel32.dll and blocks workflow execution in Linux CI/CD.

Environment

• Extension Bundle: Microsoft.Azure.Functions.ExtensionBundle.Workflows 1.165.50
• OS: Ubuntu Linux (GitHub Actions ubuntu-latest and custom Ubuntu runners)
• Azure Functions Core Tools: v4
• First observed: between 2026-05-07 and 2026-05-20
• Last known good: bundle 1.138.54 (and older versions in our pipeline)

Actual Behavior

Workflows fail at runtime with DllNotFoundException for kernel32.dll.

Key stack trace excerpt

System.DllNotFoundException: Unable to load shared library 'kernel32.dll' or one of its dependencies. 
In order to help diagnose loading problems, consider using a tool like strace. 
If you're using glibc, consider setting the LD_DEBUG environment variable: 

/usr/local/lib/node_modules/azure-functions-core-tools/bin/in-proc8/kernel32.dll.so: cannot open shared object file: No such file or directory
/home/runner/.azure-functions-core-tools/Functions/ExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle.Workflows/1.165.50/bin/kernel32.dll.so: cannot open shared object file: No such file or directory
/usr/local/lib/node_modules/azure-functions-core-tools/bin/in-proc8/libkernel32.dll.so: cannot open shared object file: No such file or directory
/home/runner/.azure-functions-core-tools/Functions/ExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle.Workflows/1.165.50/bin/libkernel32.dll.so: cannot open shared object file: No such file or directory
/usr/local/lib/node_modules/azure-functions-core-tools/bin/in-proc8/kernel32.dll: cannot open shared object file: No such file or directory
/home/runner/.azure-functions-core-tools/Functions/ExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle.Workflows/1.165.50/bin/kernel32.dll: cannot open shared object file: No such file or directory
/usr/local/lib/node_modules/azure-functions-core-tools/bin/in-proc8/libkernel32.dll: cannot open shared object file: No such file or directory
/home/runner/.azure-functions-core-tools/Functions/ExtensionBundles/Microsoft.Azure.Functions.ExtensionBundle.Workflows/1.165.50/bin/libkernel32.dll: cannot open shared object file: No such file or directory

   at Microsoft.Azure.Workflows.Common.PerformanceCounters.WebAppWorkerMemoryUsageCounter.NativeMethods.GlobalMemoryStatusEx(MEMORYSTATUSEX& lpBuffer)
   at Microsoft.Azure.Workflows.Common.PerformanceCounters.WebAppWorkerMemoryUsageCounter.ReadCounter()
   at Microsoft.Azure.Workflows.Common.PerformanceCounters.FlowPerformance.get_CurrentMemoryUtilization()
   at Microsoft.Azure.Workflows.Data.Configuration.EdgeResourceGovernancePolicy.<>c.<.ctor>b__21_0()
   at Microsoft.Azure.Workflows.Data.Configuration.EdgeResourceGovernancePolicy.ShouldThrottleWorkerPulsation(JobTriggerEvent trigger, String& throttledTraceMessage)
   at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Execution.JobDispatchingWorkerRegistry.PulseNextWaitingWorker(JobTriggerEvent trigger)
   at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Execution.JobDispatchingWorkerRegistry.PulseWorkers()
   at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.JobDispatcherClient.PulseDispatchingWorkers(CancellationToken cancellationToken)

Observed root cause after decompilation

• Assembly: Microsoft.Azure.Workflows.EventSource.Common.dll
• Namespace: Microsoft.Azure.Workflows.Common.PerformanceCounters
• Class: WebAppWorkerMemoryUsageCounter
• Method: ReadCounter()
• Uses hard-coded P/Invoke to kernel32.dll GlobalMemoryStatusEx without platform check.

Plan Type

Standard

Steps to Reproduce the Bug or Issue

Steps to Reproduce

1. Create or run a Logic App Standard project using extension bundle 1.165.50.
2. Run on Ubuntu (local container or GitHub Actions runner).
3. Start host / execute workflow.
4. Observe DllNotFoundException for kernel32.dll and workflow failure.

Workflow JSON

Screenshots or Videos

No response

Additional context

Expected Behavior

Logic Apps should execute on Linux, as supported by Azure Functions/Logic Apps and as seen in prior bundle versions.

Impact

• Severity: High
• Blocks Linux-based CI/CD for Logic Apps
• Forces temporary migration to Windows runners or bundle pinning

Workarounds

• Pin bundle version to 1.138.54 in host.json
• Use Windows runners instead of Linux
• WEBSITE_DISABLE_PERFORMANCE_COUNTERS=1 did not prevent this failure in our tests

Suggested Fix

Use cross-platform memory usage APIs, for example:

• GC.GetGCMemoryInfo()
• Process.WorkingSet64
  Or guard Windows-only calls with RuntimeInformation.IsOSPlatform(OSPlatform.Windows).

This report may be a related root cause for Linux-hosted scenarios.

[ronaldbosma]

I have similar issues.

I've updated the Microsoft.Azure.Workflows.WebJobs.Tests.Extension package to version 1.0.3 (and 1.0.2) that uses version 1.165.50 of the extension bundle and I'm seeing the same error when I run tests against my workflows. See this failed pipeline.

Stacktrace + Logging:

       at Microsoft.Azure.Workflows.Common.PerformanceCounters.WebAppWorkerMemoryUsageCounter.NativeMethods.GlobalMemoryStatusEx(MEMORYSTATUSEX& lpBuffer)
       at Microsoft.Azure.Workflows.Common.PerformanceCounters.WebAppWorkerMemoryUsageCounter.ReadCounter()
       at Microsoft.Azure.Workflows.Data.Configuration.EdgeResourceGovernancePolicy.ShouldThrottleWorkerPulsation(JobTriggerEvent trigger, String& throttledTraceMessage)
       at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Execution.JobDispatchingWorkerRegistry.CanAcquireDispatchingWorker(JobTriggerEvent trigger)
       at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Notification.IBackgroundJobsNotificationChannelExtensions.CanAcquireDispatchingWorker(IBackgroundJobsNotificationChannel notificationChannel, JobTrigger trigger)
       at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Execution.JobExecutionEngine.PrepareJobDefinitionForImmediateExecution(JobManagementClient managementClient, JobDefinition definition, JobTrigger preparedTrigger, Boolean isPartialUpdate)
       at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.Execution.JobExecutionEngine.ScheduleJobExecution(JobManagementClient managementClient, JobDefinition newDefinition, JobDefinition oldDefinition, DateTime nextExecutionTime, JobUpdateOperation jobUpdateOperation, String clientOperationId, Nullable`1 version, Func`1 onCommitJobDefinitionDelegate)
       at Microsoft.WindowsAzure.ResourceStack.Common.BackgroundJobs.JobManagementClient.CreateJob(JobBuilder builder, Func`1 onCommitJobDefinitionDelegate)
       at Microsoft.Azure.Workflows.Web.Engines.EdgeFlowWebManagementEngine.CreateNewFlow(String subscriptionId, String resourceGroup, String flowName, FlowPropertiesDefinition definitionProperties, FlowTemplateRuntimeContext runtimeContext)
       at Microsoft.Azure.Workflows.Web.Engines.EdgeFlowWebManagementEngine.ValidateAndCreateFlow(String appName, String flowName, FlowPropertiesDefinition flowPropertiesDefinition, String resourceGroup)
       at Microsoft.WindowsAzure.ResourceStack.Common.Algorithms.AsyncRetry.Retry(Func`1 action, Int32 retryCount, TimeSpan retryInterval, CancellationToken cancellationToken, Nullable`1 retryTimeout, Func`2 isRetryable, Action`1 errorAction, Func`2 retryAfter)
       at Microsoft.Azure.Workflows.WebJobs.Extensions.Initialization.WorkflowFunctionDefinitionProvider.<>c__DisplayClass107_0.<<ProcessWorkflow>b__0>d.MoveNext()
    --- End of stack trace from previous location ---
       at Microsoft.Azure.Workflows.Templates.Engines.TemplateEngine.HandleTemplateException[T](Func`1 protectedMethod, HttpStatusCode statusCode)
       at Microsoft.Azure.Workflows.WebJobs.Extensions.Initialization.WorkflowFunctionDefinitionProvider.ProcessWorkflow(FlowFunction flowFunction, ConcurrentDictionary`2 flowsProcessed)', extensionVersion='1.165.50.0', siteName='UNDEFINED_SITE_NAME', slotName='', activityId='308f7250-b791-42f8-9c14-a7a77b3848b9'. 
    Error  Workflow processing failed. Error: 'Workflow '20260601045723-97f2fcac-7513-4b45-acf2-4747841d4cfe' is unhealthy. Error:'System.DllNotFoundException: Unable to load shared library 'kernel32.dll' or one of its dependencies. In order to help diagnose loading problems, consider using a tool like strace. If you're using glibc, consider setting the LD_DEBUG environment variable: 
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/runtimes/linux-x64/native/kernel32.dll.so: cannot open shared object file: No such file or directory
    /usr/share/dotnet/shared/Microsoft.NETCore.App/8.0.27/kernel32.dll.so: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/kernel32.dll.so: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/runtimes/linux-x64/native/libkernel32.dll.so: cannot open shared object file: No such file or directory
    /usr/share/dotnet/shared/Microsoft.NETCore.App/8.0.27/libkernel32.dll.so: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/libkernel32.dll.so: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/runtimes/linux-x64/native/kernel32.dll: cannot open shared object file: No such file or directory
    /usr/share/dotnet/shared/Microsoft.NETCore.App/8.0.27/kernel32.dll: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/kernel32.dll: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/runtimes/linux-x64/native/libkernel32.dll: cannot open shared object file: No such file or directory
    /usr/share/dotnet/shared/Microsoft.NETCore.App/8.0.27/libkernel32.dll: cannot open shared object file: No such file or directory
    /home/runner/work/track-availability-in-app-insights/track-availability-in-app-insights/src/logicApp/Workflows.Tests/bin/Debug/net8.0/libkernel32.dll: cannot open shared object file: No such file or directory

My tests succeed if I run them with version 1.0.1 of the package that uses version 1.149.59.0 of the extension bundle. Search for extensionVersion in the 'Run Unit Tests for Logic App Workflows' step of this successful pipeline.

[github-actions]

This issue is stale because it has been open for 45 days with no activity.

[ronaldbosma]

There's a new version of the extension bundle in which the issue seems fixed, but Microsoft.Azure.Workflows.WebJobs.Tests.Extension still needs to be updated to use that new version.