You must specify a value for this required field

If you are using a custom masterpage it is very common to use the visible="false" tag to hide element SharePoint is looking for but you don’t want displayed on your page.  If you did this with the PlaceHolderPageTitleInTitleArea tag at first glance everything works as it should.  However, you will notice that you can no longer save pages through the UI without getting the “You must specify a value for this required field” error.

To resolve this issue. Create a css class and call it.

.hide {
visibility: hidden;
}

Then wrap your PlaceHolderPageTitleInTitleArea in a <asp:Panel> tag that looks like this…

<asp:panel runat="server" cssclass="hide">
  <asp:contentplaceholder id="PlaceHolderPageTitleInTitleArea" runat="server" />
</asp:panel>