"Saving changes is not permitted" - error when trying to save SQL changes

When I tried to save the table changes done using SQL Server R2, I got the below error all the time.

The problem was solved after the doing following changes.

To change the Prevent saving changes that require the table re-creation option, follow these steps:

1. Open SQL Server Management Studio (SSMS).
2. On the Tools menu, click Options.
3. In the navigation pane of the Options window, click Designers.
4. Select or clear the Prevent saving changes that require the table re-creation check box, and then click OK.

Note If you disable this option, you are not warned when you save the table that the changes that you made have changed the metadata structure of the table. In this case, data loss may occur when you save the table.

For more Info: http://support.microsoft.com/kb/956176

DotNetNuke (DNN) Error in Password Resetting

Error :

AssemblyVersion: 6.2.0

StackTrace:

Message: System.ArgumentNullException: Value cannot be null. Parameter name: input at System.Text.RegularExpressions.Regex.Replace(String input, String replacement) at DotNetNuke.Common.Utilities.HtmlUtils.StripWhiteSpace(String HTML, Boolean RetainSpace) at DotNetNuke.Services.Mail.Mail.SendMailInternal(MailMessage mailMessage, String subject, String body, MailPriority priority, MailFormat bodyFormat, Encoding bodyEncoding, IEnumerable`1 attachments, String smtpServer, String smtpAuthentication, String smtpUsername, String smtpPassword, Boolean smtpEnableSSL) at DotNetNuke.Services.Mail.Mail.SendEmail(String fromAddress, String senderAddress, String toAddress, String subject, String body) at DotNetNuke.Services.Mail.Mail.SendMail(UserInfo user, MessageType msgType, PortalSettings settings) at DotNetNuke.Modules.Admin.Users.ManageUsers.PasswordUpdated(Object sender, PasswordUpdatedEventArgs e) 

Solution : 

We tried out lot of things and finally finally figured out the error. It was that the subject localization key is missing in the GlobalResources.resx file. Once you add the following key 
EMAIL_USER_UPDATED_OWN_PASSWORD_SUBJECT.Text everything was working perfectly....