"Could not load file or assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'

 These days, i encounter a issue when i copy a web appplication from another PC to local , this error message is display "Could not load file or assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified." 

 Then i search the solution about this in the internet, but no correct way to resolve it.

 At laste, i get the way as blow in the communication with my  project leader

 1. check the folder which contains the application

 2. set the virtual path or directory of the application in IIS

 3. build it and success

I hope above will help you who encounter this issue either