Could not load file or assembly 'AjaxMin, Version=4.97.4951.28478, Culture=neutral, PublicKeyToken=21ef50ce11b5d80f' or one of its dependencies. The system cannot find the file specified.

The given error indicates that the project bin directory(folder) is missing AjaxMin.dll.So,in order to solve given error follow below steps:

Step 1:-Copy AjaxMin.dll from the ajaxtoolkit extracted folder.

Step 2:- Paste the above copied AjaxMin.dll file to your project bin folder.

Step 3:- Build your project.And you are good to go.

Have a great coding!!!