Error: [Could not load file or assembly exception during installation of Routing Agent]

Scenario

You are installing the Signatures for Exchange feature, and you get the following error message:
 

Reason

This error message is caused by a security feature within Windows regarding remote files.

Resolution

To resolve this issue, you can either unblock the zip from the Properties window or Windows Powershell.

To unblock the zip file via the Properties window: 

• Go to your Downloads folder, right-click the zip file from the Exclaimer portal, select Properties and select the Unblock option.
  
  
  
  - Click OK to proceed.
  
  - Unzip the files and continue with the installation.
  
  
  Helpful Tip! 
  It is recommended that you unblock the zip files on the server from where you are doing the installation (as you cannot unblock and copy the files over).  

To unblock zip file via Windows Powershell:

1. Open Windows Powershell.
   
   

2. Enter the Unblock-File command to unblock the zip file, and press [Enter] to proceed.

   Unblock-File -Path .\Exclaimer.Exchange.TransportAgent-*.zip