“You must specify a value for this required field” error when hidding PlaceHolderPageTitleInTitleArea
Instead of commenting or deleting the following code
asp:ContentPlaceHolder ID="PlaceHolderPageTitleInTitleArea" runat="server
use style="display:none;" as follows
asp:Panel style="display:none;"
asp:ContentPlaceHolder ID="PlaceHolderPageTitleInTitleArea" runat="server" /
asp:Panel
When customizing SharePoint 2010 MasterPages you often don’t want certain content placeholders to show up on the page. You should not delete or comment these elements out but instead set the visible=”false” or display:none attribute on the content placeholder.