Hi,
You could add this to your user.config to disable the search feature.
<add key="DisableSearchIndex" value="true" />
Be sure to recycle the app by touching Web.config or using the control panel, this will make it see your new setting in user.config.
Though I do consider it a bug if it throws errors when removing the search input from the layout.master. But the error message gives no real clues, is that a client side javascript error or is there a better error in the mojoportal log with a stack trace?
When I look at line 119 in he server side code there is nothing there that could possibly throw an error like this, the line looks like this:
this.txtTitle.Text = html.Title;
just setting a property on a text box, and furthermore that line of code is not even executed on postback.
Hope it helps,
Joe