Failed to Load file or assembly "system. Web. Extensions. Design, version = 1.0.61025.0, culture = neutral, publickeytoken = 31bf38

Link: http://www.cnblogs.com/Gorson/articles/1236716.html

Failed to Load file orProgramSet "system. Web. Extensions. Design, version = 1.0.61025.0, culture = neutral, publickeytoken = 31bf3856ad364e35"
Or one of its dependencies. The system cannot find the specified file.
Install Asp.net Ajax, and then set X: \ Program Files \ Microsoft ASP. NET \ ASP. NET 2.0 Ajax extensions \ v1.0.61025
Add the system. Web. Extensions. Design. dll file under the directory to the bin directory of the project. copy the file to the bin directory of the website and run it again,
After installing Asp.net Ajax, there will be three DLL files

System. Web. Extensions. Design. dll

Ajaxextensionstoolbox. dll

System. Web. Extensions. dll

Generally, you should add these three files to the bin directory of the project. If you want to insure them, copy them all.