I am a relative newcomer to SharePoint 2010 and am creating a site collection. When in SharePoint Designer 2010 I oberserve the following message on the rendering of the ribbon (of subsites only--not site pages in the top-level) "Unknown server tag 'WebPartPages:WebPartAdder'". I have googled this error message and looked at all the links that I could.
I'm trying to understand first, what does this message mean? If it has to do with a web part on a master pages, why doesn't this message appear when I render the top-level site in SharePoint Designer, or on the top-level site pages.
The only significant change to the master page that I've made is removing the quick launch via the method proposed by Randy Driscoll in the PlaceholderHolderLeftNavBar. The code inside the placeholder is:
<asp:ContentPlaceHolder id="PlaceHolderLeftNavBar" runat="server">
<!--Hiding left navigation via Drisgill-->
<style type="text/css">
#s4-leftpanel {
display:none;
}
.s4-ca {
margin-left: 0px;
}</style>
<!--End of hiding effort-->
</asp:ContentPlaceHolder>
Has my code caused a problem?
Second, there doesn't appear to be any trouble rendering the site outside of SharePoint Designer, at least that I observe when I navigate to the site. Some answers to this question on the net refer to problems with permissions. I am on the site as a site collection administrator. Shouldn't I be able to view and make changes?
Any help would be greatly appreciated. I'm not an experienced programmer, so don't be afraid to make it basic. Thanks.