title: Azure Function App failing to load IOptionsFormatter
body: <p>I have a C# Azure Function App that I'm trying to run locally. It previously had worked fine some months ago but is now failing with the following:</p>
  
  <blockquote>
    <p>A host error has occurred<br>
    Microsoft.Azure.WebJobs.Extensions.Storage: Could not load type 'Microsoft.Azure.WebJobs.Hosting.IOptionsFormatter' from assembly 'Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.</p>
  </blockquote>
  
  <p>At some point I had updated the <strong>Azure Functions and Web Jobs Tools</strong> to the latest version (15.10.20460.0).</p>
  
  <p>On startup, it was having problems indexing the functions so I updated the <strong>Microsoft.NET.Sdk.Functions</strong> nuget package reference to the latest version (1.0.24) which is now giving me the above error.</p>
  
  <p>I also added a nuget package reference to <strong>Microsoft.Azure.WebJobs.Extensions.Storage</strong> 3.0.3 to resolve the missing <code>TableAttribute</code> errors that appeared as well.</p>
  
  <p>I've checked the assemblies in the bin folder which have the following versions:</p>
  
  <ul>
  <li>Microsoft.Azure.WebJobs.Extensions.Storage.dll - v3.0.3.0</li>
  <li>Microsoft.Azure.WebJobs.Host.dll - v3.0.4.0</li>
  </ul>