“You must specify a value for this required filed” In SharePoint 2010

I was customizing SharePoint 2010 master page to hide PlaceHolderPageTitleInTitleArea and onetidProjectPropertyTitle by hiding the code.

It turn out to be a good solutions and it removed PlaceHolderPageTitleInTitleAre and onetidProjectPropertyTitle but When I try to save the changes after editing my master page, I got this error message “ You must specify a value for this required filed”

To remove this error message “You must specify a value for this required filed” I found a solutions from http://blogs.msdn.com/b/tmathis/archive/2010/03/18/you-must-specify-a-value-for-this-required-field-error-when-hidding-placeholderpagetitleintitlearea.aspx

added some of the steps I went through to resolve this problem

Step 1:

In corev4.css I added

.hiddenpanel
{
visibility:hidden;
}

Step 2:

Open your master page and this to your code