Facing issue when try to change the table structure in MSSQL 2012
"Saving changes is not permitted. The changes 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"
To solve this issue,
In Management Studio, click menu Tools -> Options -> Designers-> Uncheck "Prevent saving changes that require table re-creation
Go to change the table structure again, now it's work.
Hope this helps.