Could not load file or assembly 'Microsoft.Bot.Connector, Version=3.12.2.4, Culture=neutral, PublicKeyToken=##' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Could not load file or assembly 'Microsoft.Bot.Connector, Version=3.12.2.4, Culture=neutral, PublicKeyToken=##' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

On using c#

Could not load file or assembly 'Microsoft.Bot.Connector, Version=3.12.2.4, Culture=neutral, PublicKeyToken=##' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Error 

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Bot.Connector, Version=3.12.2.4, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Reason

 Microsoft.Bot.Builder library got update to Version=3.12.2.4

Resolution

Update the Microsoft.Bot.Builder library to latest version

Right Click on your Project and Click on manage NuGet Packages

Search for Microsoft.Bot.Connector and click on update  

Then press on accept

Hope It helps

Happy Coding 😊

SOURCE : mscrm.com