SQL Server - Saving changes is not permitted

If you get the following error message when you re-design the table and couldn't save it:

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

You can simply resolve it by following steps:

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

Reference:

http://stackoverflow.com/questions/6810425/saving-changes-is-not-permitted-in-sql-server