Error building configuration in an external startup class. Getting the below error while upgrading Function app from 3.x to 4.x . Even though all the packages are upgraded to latest versions asked getting the same error

Question

Microsoft.Azure.WebJobs.Script.ExternalStartupException : Error building configuration in an external startup class. ---> Microsoft.Azure.WebJobs.Script.HostInitializationException : One or more loaded extensions do not meet the minimum requirements. For more information see https://aka.ms/func-min-extension-versions. ExtensionStartupType EventHubsWebJobsStartup from assembly 'Microsoft.Azure.WebJobs.EventHubs, Version=4.2.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not meet the required minimum version of 4.3.0.0. Update your NuGet package reference for Microsoft.Azure.WebJobs.Extensions.EventHubs to 4.3.0 or later. ExtensionStartupType AzureStorageWebJobsStartup from assembly 'Microsoft.Azure.WebJobs.Extensions.Storage, Version=3.0.10.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not meet the required minimum version of 4.0.4.0. Update your NuGet package reference for Microsoft.Azure.WebJobs.Extensions.Storage to 4.0.4 or later. ExtensionStartupType ServiceBusWebJobsStartup from assembly 'Microsoft.Azure.WebJobs.ServiceBus, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not meet the required minimum version of 4.2.1.0. Update your NuGet package reference for Microsoft.Azure.WebJobs.Extensions.ServiceBus to 4.2.1 or later. at Microsoft.Azure.WebJobs.Script.DependencyInjection.ScriptStartupTypeLocator.ValidateExtensionRequirements(List1 startupTypes) at /_/src/WebJobs.Script/DependencyInjection/ScriptStartupTypeLocator.cs : 336 at async Microsoft.Azure.WebJobs.Script.DependencyInjection.ScriptStartupTypeLocator.GetExtensionsStartupTypesAsync() at /_/src/WebJobs.Script/DependencyInjection/ScriptStartupTypeLocator.cs : 222 at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.Azure.WebJobs.Script.DependencyInjection.ScriptStartupTypeLocator.<.ctor>b__10_0() at /_/src/WebJobs.Script/DependencyInjection/ScriptStartupTypeLocator.cs : 53 at System.Lazy1.ViaFactory(LazyThreadSafetyMode mode) at System.Lazy1.ExecutionAndPublication(LazyHelper executionAndPublication,Boolean useDefaultConstructor) at System.Lazy1.CreateValue() at System.Lazy`1.get_Value() at Microsoft.Azure.WebJobs.Script.DependencyInjection.ScriptStartupTypeLocator.GetStartupTypes() at //src/WebJobs.Script/DependencyInjection/ScriptStartupTypeLocator.cs : 68 at Microsoft.Azure.WebJobs.WebJobsBuilderExtensions.UseExternalConfigurationStartup(IWebJobsConfigurationBuilder builder,IWebJobsStartupTypeLocator startupTypeLocator,WebJobsBuilderContext context,ILoggerFactory loggerFactory) at D:\a_work\1\s\src\Microsoft.Azure.WebJobs.Host\Hosting\WebJobsBuilderExtensions.cs : 362 at Microsoft.Azure.WebJobs.Script.ScriptHostBuilderExtensions.<>c__DisplayClass7_3.<AddScriptHostCore>b__8(IWebJobsStartupTypeLocator locator) at //src/WebJobs.Script/ScriptHostBuilderExtensions.cs : 258 End of inner exception

Answer 1

Hi @Vikas Rajareddy

Just to confirm, you've updated all your extensions to a version (or higher) listed below:

Check	Extension	Minimum Version
✔️	Microsoft.Azure.WebJobs.Extensions.Storage	4.0.4
✔️	Microsoft.Azure.WebJobs.Extensions.ServiceBus	4.2.1
✔️	Microsoft.Azure.WebJobs.Extensions.EventHubs	4.3.0
	Microsoft.Azure.WebJobs.Extensions.DurableTask	2.4.1
	Microsoft.Azure.WebJobs.Extensions.CosmosDB	3.0.9
	Microsoft.Azure.WebJobs.Extensions.EventGrid	2.1.0
	Microsoft.Azure.WebJobs.Extensions.RabbitMQ	1.0.0
	Microsoft.Azure.WebJobs.Extensions.Kafka	3.2.1

According to the exception, it's loading versions lower than what's required. I would check your nuget references by inspecting packages.config or <PackageReference/> in the csproj. At the solution level, if you have mismatched versions, this could cause an issue. You may have binding redirects that's not pointing the correct version.

Answer 2

Hello @VikasRajareddy-9365

This error message indicates that there is an issue with the version of some of the extensions that are being used in your Azure Functions project.

To resolve this issue, you need to update the NuGet package references for the affected extensions to the required minimum versions. Specifically, you should update the

Microsoft.Azure.WebJobs.Extensions.EventHubs package to version 4.3.0 or later, the Microsoft.Azure.WebJobs.Extensions.Storage package to version 4.0.4 or later, and the Microsoft.Azure.WebJobs.Extensions.ServiceBus package to version 4.2.1 or later.

Once you have updated the package references, restart your IDE, rebuild your project and try running it again.

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I hope this helps further