[A]System.AppDomain cannot be cast to [B]System.AppDomain

[kornakar]

When trying to run a ServiceBusTrigger function in development environment, I get following exceptions in the Diagnostics Tool's Event window. This happens even with a fresh solution and project. This may be related to #2786.

Investigative information

Local development environment
Windows 10
Visual Studio 2017 Enterprise 15.6.4
Azure Functions and Web Jobs 15.0.40502.0

Function App version: 3.0.0-beta5
Sdk.Functions version: 1.0.13
netstandard2

Repro steps

• Create a new solution with Azure Function (Azure Functions v2 Preview (.NET Standard))
• Use development storage (UseDevelopmentStorage=true)
• Use any valid connection string (note that QueueTrigger and ServiceBusTriggers use different connection strings)
• Add nuget package: Install-Package Microsoft.Azure.WebJobs.ServiceBus -Version 3.0.0-beta5
• Change QueueTriggerAttribute to ServiceBusTriggerAttribute in the Function1.Run method
• Run the project

Actual behavior

Console output:

[16/05/2018 11.39.29] Host configuration file read:
[16/05/2018 11.39.29] {}
[16/05/2018 11.39.29] Starting Host (HostId=echelwjvai2-236828010, InstanceId=758df03a-d168-4782-877d-a8562079faa5, Version=2.0.11651.0, ProcessId=16856, AppDomainId=1, Debug=False, ConsecutiveErrors=0, StartupCount=1, FunctionsExtensionVersion=)
[16/05/2018 11.39.29] Unable to configure java worker. Could not find JAVA_HOME app setting.
[16/05/2018 11.39.29]
[16/05/2018 11.39.29] Could not configure language worker Java.
[16/05/2018 11.39.29]
[16/05/2018 11.39.30] Loaded custom extension: ServiceBusExtensionConfig from 'referenced by: Method='FunctionApp1.Function1.Run', Parameter='myQueueItem'.'
[16/05/2018 11.39.30] Generating 1 job function(s)
[16/05/2018 11.39.30] Found the following functions:
[16/05/2018 11.39.30] FunctionApp1.Function1.Run
[16/05/2018 11.39.30]
[16/05/2018 11.39.30] Host initialized (1290ms)
Listening on http://localhost:7071/
Hit CTRL-C to exit...
[16/05/2018 11.39.31] Host started (1920ms)
[16/05/2018 11.39.31] Job host started
[16/05/2018 11.39.31] Host lock lease acquired by instance ID '00000000000000000000000010A97A99'.

Exception in the Diagnostics Tool event window:

Exception: Exception thrown: 'System.InvalidCastException' in Microsoft.Azure.WebJobs.Script.dll ("[A]System.AppDomain cannot be cast to [B]System.AppDomain. Type A originates from 'System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e' in the context 'Default' at location 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.6\System.Private.CoreLib.dll'. Type B originates from 'System.Runtime.Extensions, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' in the context 'Default' at location 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.6\System.Runtime.Extensions.dll'."). Exception thrown: 'System.InvalidCastException' in Microsoft.Azure.WebJobs.Script.dll ("[A]System.AppDomain cannot be cast to [B]System.AppDomain. Type A originates from 'System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e' in the context 'Default' at location 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.6\System.Private.CoreLib.dll'. Type B originates from 'System.Runtime.Extensions, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' in the context 'Default' at location 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.6\System.Runtime.Extensions.dll'.") 2.87s [17352] Worker Thread

Related information

Source

    public static class Function1
    {
        [FunctionName("Function1")]
        public static void Run([ServiceBusTrigger("myqueuename", Connection = "QueueConnectionString")]string myQueueItem, TraceWriter log)
        {
            log.Info($"C# Queue trigger function processed: {myQueueItem}");
        }
    }

[paulbatum]

This has been resolved, and there is currently a deployment in progress with the fix. You should see this error disappear by the end of the week.