<p>The application is in Azure Functions,</p>
<p>The error that we are getting from container Pod logs is &quot;Could not load type 'Microsoft.Azure.WebJobs.Host.Scale.ConcurrencyManager' from assembly 'Microsoft.Azure.WebJobs.Host, Version=3.0.26.0&quot;.</p>
<p>In our application version all of the dll ver is 3.0.30.0</p>
<p><a href="https://i.stack.imgur.com/lJ5d4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lJ5d4.png" alt="enter image description here" /></a></p>
<p>In the &quot;dll&quot; folder of debug is having the version with 3.0.30.0</p>
<p><a href="https://i.stack.imgur.com/pAuTW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pAuTW.png" alt="enter image description here" /></a></p>
<p>And in this version 3.0.30.0, it has the class &quot;Microsoft.Azure.WebJobs.Host.Scale.ConcurrencyManager&quot;</p>
<p><a href="https://i.stack.imgur.com/OGWuc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OGWuc.png" alt="enter image description here" /></a></p>
<p>Not sure, where this &quot;assembly 'Microsoft.Azure.WebJobs.Host, Version=3.0.26.0&quot; is coming from.</p>

<p>For me this was happening because <strong>Azure Functions Core Tools</strong> version mismatched due to upgradation of <strong>Visual Studio</strong> to latest version.
Removing the Azure Function Tools from the system path <code>C:\Users\user.name\AppData\Local\AzureFunctionsTools</code> and Let Visual Studio automatically install <strong>Azure Functions Core Tools</strong> fixed the issue.</p>
