Error 3027 in entity framework

Go to Solution Explorer, click the Search button, leave checked both "Search within file content" and "Search External Files", type the entities name your mapping isn't recognizing. Delete all files RELATED to the problem. Those will probably be named after the same missing entity. DO NOT delete any file with your Context Class name on the file, specially if their extensions are .cs or .tt. In the Context .cs file, remove all lines of codes referencing the missing entity. They will look like this:

public virtual DbSet< COUNTRies> COUNTRies { get; set; }

This error is common to tables deleted from the database. You drop a table in the database, or you just change your web.config.connectionStrings for the EF Mapped database, pointing to a new, not the one you used to generate the original mappings and in this new db these entities with the 3027 error aren't present.