MVc:Type is not resolved for member 'MySql.Data.MySqlClient.

Question

using code first approch  whlle update database  getting error:-

   

Type is not resolved for member 'MySql.Data.MySqlClient.MySqlException,MySql.Data, Version=6.9.9.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d'. 

 

 

 

note:- while creating table in database works fine but when we do some modification in code

        (alter any columns) then getting above error.