Error : Validation of viewstate MAC failed. If this application is hosted by a Web Farm....

Generate machine key from here 
http://www.orcsweb.com/articles/generate-aspnet-machine-key/

then add to web.config


   
   
   

       

   

fix msyql odbc 64 bit for thai language

use msyql odbc connector 5.1.5 and create USN data source

http://ftp.nchu.edu.tw/MySQL/downloads/connector/odbc/5.1.html#winx64