Specified key was too long; Max key length is 767 bytes MySQL

Specified key was too long; Max key length is 767 bytes

Description: An unhandled exception occurred during the execution of the current WEB request. Check the stack trace information For more information about the error and the source of the error in your code.

Exception Details: MySql.Data.MySqlClient.MySqlException:Specified key was too long; Max key length is 767 bytes

Add the following annotations to the context

[Dbconfigurationtype (typeof (MySql.Data.Entity.MySqlEFConfiguration))]
public class Mycontext:dbcontext
{
}

Specified key was too long; Max key length is 767 bytes MySQL