How to fix Error: Refresh ObjectStateManager entries in MVC 4

I want to  insert into 2 table in 1 controller: example: 

db.Entry(record).State = EntityState.Added;
db.SaveChanges();
//
db.OtherTable.Add(newRecord);
db.SaveChanges(); //Error here

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries