Prevent saving changes that require the table re-creation

Saving changes is not permitted. The changes that you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created., 

When we get Below Error Message While Modifying table...Then,

To change this option, on the Tools menu, click Options, expand Designers, 
and then click Table and Database Designers. Select or UnSelect the
Prevent saving changes that require the table to be re-created check box.