Saving changes is not permitted in SQL Server

From Save (not permitted) Dialog Box on MSDN:

the  Save   (not permitted) dialog box warns you saving changes are not Permi tted because the changes you had made require the listed tables to be dropped and re-created.

The following actions might require a table to be re-created:

• Adding A new column to the middle of the table
• dropping a column
• changing column Nullabil ity
• Changing the order of the columns
• changing the data type of a column  <<<&L t;

To change this option, 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.

See Also Colt Kwong Blog Entry:
Saving changes isn't permitted in SQL Management Studio

Saving changes is not permitted in SQL Server