When using a custom master page and editing a page in SharePoint 2010 I received a dialog box the following error:
“You must specify a value for this required field”.
This error is caused when you set the contentplaceholder ‘PlaceHolderPageTitleInTitleArea’ to: Visible=”False”. After removing the Visible=False attribute from the contentplaceholder the error disappeared.
As a workaround you can wrap the contentplaceholder in a <div> and hide the div with a little CSS. That way the contentplaceholder is still in place but hidden for the user.
<div style="display: none;"> <asp:ContentPlaceHolder id="PlaceHolderPageTitleInTitleArea" runat="server" > </asp:ContentPlaceHolder> </div>
Hope it helps.